Added auto completion of download java docs and src artifacts

Author: Torstein Krause Johansen

bash_completion.d/mvn

@@ -35,6 +35,8 @@ options="
   -B
   -C
   -D
+  -DdownloadJavadocs
+  -DdownloadSources
   -Dmaven.test.failure.ignore=false
   -Dmaven.test.skip=true
   -DskipTests