Replace deprecated toString methods (#126)

diff --git a/src/main/java/org/apache/maven/plugins/help/DescribeMojo.java b/src/main/java/org/apache/maven/plugins/help/DescribeMojo.java
index 19a8118..522bd39 100644
--- a/src/main/java/org/apache/maven/plugins/help/DescribeMojo.java
+++ b/src/main/java/org/apache/maven/plugins/help/DescribeMojo.java
@@ -209,6 +209,7 @@
     /**
      * {@inheritDoc}
      */
+    @Override
     public void execute() throws MojoExecutionException, MojoFailureException {
         StringBuilder descriptionBuffer = new StringBuilder();
 
@@ -397,7 +398,7 @@
                 name = pd.getId();
             }
         }
-        append(buffer, "Name", MessageUtils.buffer().strong(name).toString(), 0);
+        append(buffer, "Name", MessageUtils.buffer().strong(name).build(), 0);
         appendAsParagraph(buffer, "Description", toDescription(pd.getDescription()), 0);
         append(buffer, "Group Id", pd.getGroupId(), 0);
         append(buffer, "Artifact Id", pd.getArtifactId(), 0);
@@ -405,7 +406,7 @@
         append(
                 buffer,
                 "Goal Prefix",
-                MessageUtils.buffer().strong(pd.getGoalPrefix()).toString(),
+                MessageUtils.buffer().strong(pd.getGoalPrefix()).build(),
                 0);
         buffer.append(LS);
 
@@ -469,7 +470,7 @@
      */
     private void describeMojoGuts(MojoDescriptor md, StringBuilder buffer, boolean fullDescription)
             throws MojoFailureException, MojoExecutionException {
-        append(buffer, MessageUtils.buffer().strong(md.getFullGoalName()).toString(), 0);
+        append(buffer, MessageUtils.buffer().strong(md.getFullGoalName()).build(), 0);
 
         // indent 1
         appendAsParagraph(buffer, "Description", toDescription(md.getDescription()), 1);
@@ -482,7 +483,7 @@
         if (deprecation != null && !deprecation.isEmpty()) {
             append(
                     buffer,
-                    MessageUtils.buffer().warning("Deprecated. " + deprecation).toString(),
+                    MessageUtils.buffer().warning("Deprecated. " + deprecation).build(),
                     1);
         }
 
@@ -612,7 +613,7 @@
                         buffer,
                         MessageUtils.buffer()
                                 .warning("Deprecated. " + deprecation)
-                                .toString(),
+                                .build(),
                         3);
             }
         }
diff --git a/src/main/java/org/apache/maven/plugins/help/EffectivePomMojo.java b/src/main/java/org/apache/maven/plugins/help/EffectivePomMojo.java
index 4e42148..c38e2c5 100644
--- a/src/main/java/org/apache/maven/plugins/help/EffectivePomMojo.java
+++ b/src/main/java/org/apache/maven/plugins/help/EffectivePomMojo.java
@@ -90,6 +90,7 @@
     // ----------------------------------------------------------------------
 
     /** {@inheritDoc} */
+    @Override
     public void execute() throws MojoExecutionException {
         if (artifact != null && !artifact.isEmpty()) {
             project = getMavenProject(artifact);
@@ -131,7 +132,7 @@
         } else {
             if (MessageUtils.isColorEnabled()) {
                 // add color to comments
-                String comment = MessageUtils.buffer().project("<!--.-->").toString();
+                String comment = MessageUtils.buffer().project("<!--.-->").build();
                 int dotIndex = comment.indexOf(".");
                 String commentStart = comment.substring(0, dotIndex);
                 String commentEnd = comment.substring(dotIndex + 1);