Sort dependencies in POMs

Improves the `src/tools/sort-pom.xslt` stylesheet to sort dependencies in the
POM files according to the scope, artifact id (with a priority for Logj2
artifacts) and group id.

It uses this script to automatically sort all POM files.
diff --git a/log4j-flume-ng/pom.xml b/log4j-flume-ng/pom.xml
index b621771..ca04b71 100644
--- a/log4j-flume-ng/pom.xml
+++ b/log4j-flume-ng/pom.xml
@@ -43,55 +43,45 @@
       <artifactId>log4j-core</artifactId>
     </dependency>
     <dependency>
+      <groupId>org.apache.flume</groupId>
+      <artifactId>flume-ng-core</artifactId>
+      <optional>true</optional>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.flume</groupId>
+      <artifactId>flume-ng-embedded-agent</artifactId>
+      <optional>true</optional>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.flume</groupId>
+      <artifactId>flume-ng-sdk</artifactId>
+    </dependency>
+    <dependency>
       <groupId>com.sleepycat</groupId>
       <artifactId>je</artifactId>
     </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
-      <artifactId>log4j-slf4j-impl</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-1.2-api</artifactId>
       <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
-      <artifactId>log4j-jcl</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.logging.log4j</groupId>
       <artifactId>log4j-core</artifactId>
       <type>test-jar</type>
       <scope>test</scope>
     </dependency>
     <dependency>
-      <groupId>org.junit.vintage</groupId>
-      <artifactId>junit-vintage-engine</artifactId>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-jcl</artifactId>
       <scope>test</scope>
     </dependency>
     <dependency>
-      <groupId>org.junit.jupiter</groupId>
-      <artifactId>junit-jupiter-engine</artifactId>
+      <groupId>org.apache.logging.log4j</groupId>
+      <artifactId>log4j-slf4j-impl</artifactId>
       <scope>test</scope>
     </dependency>
     <dependency>
-      <groupId>org.apache.flume</groupId>
-      <artifactId>flume-ng-sdk</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.flume</groupId>
-      <artifactId>flume-ng-core</artifactId>
-      <optional>true</optional>
-    </dependency>
-    <dependency>
-      <groupId>org.apache.flume</groupId>
-      <artifactId>flume-ng-embedded-agent</artifactId>
-      <optional>true</optional>
-    </dependency>
-    <dependency>
       <groupId>org.apache.flume.flume-ng-channels</groupId>
       <artifactId>flume-file-channel</artifactId>
       <scope>test</scope>
@@ -102,6 +92,16 @@
       <scope>test</scope>
     </dependency>
     <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.vintage</groupId>
+      <artifactId>junit-vintage-engine</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
       <groupId>io.netty</groupId>
       <artifactId>netty-all</artifactId>
       <scope>test</scope>
@@ -110,6 +110,17 @@
   <build>
     <plugins>
       <plugin>
+        <groupId>org.apache.felix</groupId>
+        <artifactId>maven-bundle-plugin</artifactId>
+        <configuration>
+          <instructions>
+            <Fragment-Host>org.apache.logging.log4j.core</Fragment-Host>
+            <Bundle-SymbolicName>org.apache.logging.log4j.flume</Bundle-SymbolicName>
+            <Export-Package>org.apache.logging.log4j.flume.appender</Export-Package>
+          </instructions>
+        </configuration>
+      </plugin>
+      <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jar-plugin</artifactId>
         <executions>
@@ -146,17 +157,6 @@
           </execution>
         </executions>
       </plugin>
-      <plugin>
-        <groupId>org.apache.felix</groupId>
-        <artifactId>maven-bundle-plugin</artifactId>
-        <configuration>
-          <instructions>
-            <Fragment-Host>org.apache.logging.log4j.core</Fragment-Host>
-            <Bundle-SymbolicName>org.apache.logging.log4j.flume</Bundle-SymbolicName>
-            <Export-Package>org.apache.logging.log4j.flume.appender</Export-Package>
-          </instructions>
-        </configuration>
-      </plugin>
     </plugins>
   </build>
   <reporting>
@@ -195,9 +195,9 @@
         <artifactId>maven-javadoc-plugin</artifactId>
         <version>${javadoc.plugin.version}</version>
         <configuration>
-          <bottom><![CDATA[<p align="center">Copyright &#169; {inceptionYear}-{currentYear} {organizationName}. All Rights Reserved.<br />
+          <bottom>&lt;p align="center"&gt;Copyright &amp;#169; {inceptionYear}-{currentYear} {organizationName}. All Rights Reserved.&lt;br /&gt;
             Apache Logging, Apache Log4j, Log4j, Apache, the Apache feather logo, the Apache Logging project logo,
-            and the Apache Log4j logo are trademarks of The Apache Software Foundation.</p>]]></bottom>
+            and the Apache Log4j logo are trademarks of The Apache Software Foundation.&lt;/p&gt;</bottom>
           <!-- module link generation is completely broken in the javadoc plugin for a multi-module non-aggregating
                project -->
           <detectOfflineLinks>false</detectOfflineLinks>
@@ -213,10 +213,6 @@
         </reportSets>
       </plugin>
       <plugin>
-        <groupId>com.github.spotbugs</groupId>
-        <artifactId>spotbugs-maven-plugin</artifactId>
-      </plugin>
-      <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jxr-plugin</artifactId>
         <version>${jxr.plugin.version}</version>
@@ -243,7 +239,10 @@
           <targetJdk>${maven.compiler.target}</targetJdk>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>com.github.spotbugs</groupId>
+        <artifactId>spotbugs-maven-plugin</artifactId>
+      </plugin>
     </plugins>
   </reporting>
 </project>
-