Move extension source to a common place

Move source code of all Meterpreter extensions to a common target
directory during build, so that tests that apply to all extensions won't
need to be updated when a new extension is added.

Use this to apply the version compatibility checks to all extensions.

java/meterpreter/stdapi/pom.xml

@@ -26,6 +26,27 @@
 	<build>
 		<finalName>ext_server_stdapi</finalName>
 		<plugins>
+			<plugin>
+				<artifactId>maven-antrun-plugin</artifactId>
+				<version>1.7</version>
+				<executions>
+					<execution>
+						<id>copy-source</id>
+						<phase>generate-sources</phase>
+						<goals>
+							<goal>run</goal>
+						</goals>
+						<configuration>
+							<target>
+								<mkdir dir="${project.basedir}/../meterpreter/target/extension-src" />
+								<copy todir="${project.basedir}/../meterpreter/target/extension-src">
+									<fileset dir="${project.basedir}/src/main/java" includes="**/*.java" />
+								</copy>
+							</target>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-jar-plugin</artifactId>

java/version-compatibility-check/java16/pom.xml

@@ -30,7 +30,7 @@
 									<fileset dir="${project.basedir}/../../javapayload/src/main/java" includes="**/*.java" excludes="rmi/**" />
 									<fileset dir="${project.basedir}/../../meterpreter/meterpreter/src/main/java" includes="**/*.java"/>
 									<!-- Webcam_audio_record_V1_4 depends on Sun proprietary API -->
-									<fileset dir="${project.basedir}/../../meterpreter/stdapi/src/main/java" includes="**/*.java" excludes="**/webcam_audio_record_V1_4.java" />
+									<fileset dir="${project.basedir}/../../meterpreter/meterpreter/target/extension-src" includes="**/*.java" excludes="**/webcam_audio_record_V1_4.java" />
 								</copy>
 							</target>
 						</configuration>