TAP5-2720: better JavaDoc for CORS symbols
diff --git a/tapestry-core/src/main/java/org/apache/tapestry5/SymbolConstants.java b/tapestry-core/src/main/java/org/apache/tapestry5/SymbolConstants.java
index 2206e47..d761905 100644
--- a/tapestry-core/src/main/java/org/apache/tapestry5/SymbolConstants.java
+++ b/tapestry-core/src/main/java/org/apache/tapestry5/SymbolConstants.java
@@ -729,7 +729,7 @@
     
     /**
      * Comma-delimited of origins allowed for CORS. The special value "*" means allowing all origins.
-     * This is used by {@link CorsHandlerHelper#getAllowedOrigin(javax.servlet.http.HttpServletRequest)}.
+     * This is used by the default implementation of {@link CorsHandlerHelper#getAllowedOrigin(javax.servlet.http.HttpServletRequest)}.
      * Default value is the empty string (i.e. no origins allowed and CORS actually disabled).
      * This is an alias for {@link TapestryHttpSymbolConstants#CORS_ALLOWED_ORIGINS}.
      * @since 5.8.2
@@ -739,7 +739,7 @@
     /**
      * Boolean value defining whether the Access-Control-Allow-Credentials HTTP header
      * should be set automatically in the response for CORS requests. Default value is
-     * <code>false</code>. This is used in {@link CorsHandlerHelper#configureCredentials(javax.servlet.http.HttpServletResponse)}.
+     * <code>false</code>. This is used by the default implementation of {@link CorsHandlerHelper#configureCredentials(javax.servlet.http.HttpServletResponse)}.
      * This is an alias for {@link TapestryHttpSymbolConstants#CORS_ALLOW_CREDENTIALS}.
      * @since 5.8.2
      */
@@ -747,7 +747,7 @@
 
     /**
      * Value to be used in the Access-Control-Allow-Methods in CORS preflight request responses.
-     * This is used by {@link CorsHandlerHelper#configureMethods(javax.servlet.http.HttpServletResponse)}.
+     * This is used by the default implementation of {@link CorsHandlerHelper#configureMethods(javax.servlet.http.HttpServletResponse)}.
      * Default value is <code>GET,HEAD,PUT,PATCH,POST,DELETE</code>.
      * This is an alias for {@link TapestryHttpSymbolConstants#CORS_ALLOW_METHODS}.
      * @since 5.8.2
@@ -755,8 +755,8 @@
     public static final String CORS_ALLOW_METHODS = TapestryHttpSymbolConstants.CORS_ALLOW_METHODS;
 
     /**
-     * Value to be used in the Access-Control-Allow-Methods in CORS preflight request responses.
-     * This is used by {@link CorsHandlerHelper#configureAllowedHeaders(javax.servlet.http.HttpServletResponse, javax.servlet.http.HttpServletRequest)}.
+     * Value to be used in the Access-Control-Allow-Headers in CORS preflight request responses.
+     * This is used by the default implementation of {@link CorsHandlerHelper#configureAllowedHeaders(javax.servlet.http.HttpServletResponse, javax.servlet.http.HttpServletRequest)}.
      * Default value is the empty string.
      * This is an alias for {@link TapestryHttpSymbolConstants#CORS_ALLOWED_HEADERS}.
      * @since 5.8.2
@@ -765,7 +765,7 @@
     
     /**
      * Value to be used in the Access-Control-Expose-Headers in CORS request responses.
-     * This is used by {@link CorsHandlerHelper#configureExposeHeaders(javax.servlet.http.HttpServletResponse)}.
+     * This is used by the default implementation of {@link CorsHandlerHelper#configureExposeHeaders(javax.servlet.http.HttpServletResponse)}.
      * Default value is the empty string.
      * This is an alias for {@link TapestryHttpSymbolConstants#CORS_EXPOSE_HEADERS}.
      * @since 5.8.2
@@ -774,7 +774,7 @@
 
     /**
      * Value to be used in the Access-Control-Max-Age in responses to preflight CORS requests.
-     * This is used by {@link CorsHandlerHelper#configureMaxAge(javax.servlet.http.HttpServletResponse)}.
+     * This is used by the default implementation of {@link CorsHandlerHelper#configureMaxAge(javax.servlet.http.HttpServletResponse)}.
      * Default value is the empty string.
      * This is an alias for {@link TapestryHttpSymbolConstants#CORS_MAX_AGE}.
      * @since 5.8.2
diff --git a/tapestry-http/src/main/java/org/apache/tapestry5/http/TapestryHttpSymbolConstants.java b/tapestry-http/src/main/java/org/apache/tapestry5/http/TapestryHttpSymbolConstants.java
index f246069..a0a4b35 100644
--- a/tapestry-http/src/main/java/org/apache/tapestry5/http/TapestryHttpSymbolConstants.java
+++ b/tapestry-http/src/main/java/org/apache/tapestry5/http/TapestryHttpSymbolConstants.java
@@ -148,7 +148,7 @@
 
     /**
      * Comma-delimited of origins allowed for CORS. The special value "*" means allowing all origins.
-     * This is used by {@link CorsHandlerHelper#getAllowedOrigin(javax.servlet.http.HttpServletRequest)}.
+     * This is used by the default implementation of {@link CorsHandlerHelper#getAllowedOrigin(javax.servlet.http.HttpServletRequest)}.
      * Default value is the empty string (i.e. no origins allowed and CORS actually disabled).
      * @since 5.8.2
      */
@@ -157,7 +157,7 @@
     /**
      * Boolean value defining whether the Access-Control-Allow-Credentials HTTP header
      * should be set automatically in the response for CORS requests. Default value is
-     * <code>false</code>. This is used in {@link CorsHandlerHelper#configureCredentials(javax.servlet.http.HttpServletResponse)}.
+     * <code>false</code>. This is used by the default implementation of {@link CorsHandlerHelper#configureCredentials(javax.servlet.http.HttpServletResponse)}.
      * @since 5.8.2
      */
     public static final String CORS_ALLOW_CREDENTIALS = "tapestry.cors-allow-credentials";
@@ -171,8 +171,9 @@
     public static final String CORS_ALLOW_METHODS = "tapestry.cors-allow-methods";
     
     /**
-     * Value to be used in the Access-Control-Allow-Methods in CORS preflight request responses.
-     * This is used by {@link CorsHandlerHelper#configureAllowedHeaders(javax.servlet.http.HttpServletResponse, javax.servlet.http.HttpServletRequest)}.
+     * Value to be used in the Access-Control-Allow-Headers in CORS preflight request responses.
+     * This is used by {@link CorsHandlerHelper#configureAllowedHeaders(javax.servlet.http.HttpServletResponse, javax.servlet.http.HttpServletRequest)},
+     * which only sets the header if the value isn't empty.
      * Default value is the empty string.
      * @since 5.8.2
      */
@@ -180,7 +181,8 @@
     
     /**
      * Value to be used in the Access-Control-Expose-Headers in CORS preflight request responses.
-     * This is used by {@link CorsHandlerHelper#configureExposeHeaders(javax.servlet.http.HttpServletResponse)}.
+     * This is used by the default implementation of {@link CorsHandlerHelper#configureExposeHeaders(javax.servlet.http.HttpServletResponse)},
+     * which only sets the header if the value isn't empty.
      * Default value is the empty string.
      * @since 5.8.2
      */
@@ -188,7 +190,8 @@
     
     /**
      * Value to be used in the Access-Control-Max-Age in responses to preflight CORS requests.
-     * This is used by {@link CorsHandlerHelper#configureMaxAge(javax.servlet.http.HttpServletResponse)}.
+     * This is used by {@link CorsHandlerHelper#configureMaxAge(javax.servlet.http.HttpServletResponse)},
+     * which only sets the header if the value isn't empty.
      * Default value is the empty string.
      * This is an alias for {@link TapestryHttpSymbolConstants#CORS_MAX_AGE}.
      * @since 5.8.2