Revert "Merge remote-tracking branch 'origin/2.x' into 2.x-docgen"

This reverts commit c8d60bc535907d1969d08649319a1e27eb473dd2, reversing
changes made to af045db99eb0e811e4d9000fd422255c7a9592b2.
diff --git a/log4j-flume-ng/.log4j-plugin-processing-activator b/log4j-flume-ng/.log4j-plugin-processing-activator
deleted file mode 100644
index ba133f3..0000000
--- a/log4j-flume-ng/.log4j-plugin-processing-activator
+++ /dev/null
@@ -1 +0,0 @@
-This file is here to activate the `plugin-processing` Maven profile.
diff --git a/log4j-flume-ng/pom.xml b/log4j-flume-ng/pom.xml
index 6af2f7c..c3bffe0 100644
--- a/log4j-flume-ng/pom.xml
+++ b/log4j-flume-ng/pom.xml
@@ -16,21 +16,17 @@
   ~ limitations under the License.
   -->
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
-
   <modelVersion>4.0.0</modelVersion>
-
   <parent>
     <groupId>org.apache.logging.log4j</groupId>
     <artifactId>log4j</artifactId>
     <version>${revision}</version>
     <relativePath>../log4j-parent</relativePath>
   </parent>
-
   <artifactId>log4j-flume-ng</artifactId>
-
+  <packaging>jar</packaging>
   <name>Apache Log4j Flume Bridge</name>
   <description>The Apache Log4j Flume Appender</description>
-
   <properties>
 
     <!--
@@ -43,7 +39,6 @@
     </bnd-extra-module-options>
     <Fragment-Host>org.apache.logging.log4j.core</Fragment-Host>
   </properties>
-
   <dependencies>
     <dependency>
       <groupId>org.apache.logging.log4j</groupId>
@@ -118,4 +113,26 @@
     </dependency>
   </dependencies>
 
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <!--
+            ~ Modules that contain `log4j-core` plugins, must be compiled with:
+            ~
+            ~   org.apache.logging.log4j.core.config.plugins.processor.PluginProcessor
+            -->
+          <annotationProcessorPaths combine.children="append">
+            <path>
+              <groupId>org.apache.logging.log4j</groupId>
+              <artifactId>log4j-core</artifactId>
+              <version>${project.version}</version>
+            </path>
+          </annotationProcessorPaths>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
 </project>