Added Java plugin.

plugins/available/java.plugin.bash

@@ -0,0 +1,11 @@
+cite about-plugin
+about-plugin 'Java and JAR helper functions'
+
+function jar_manifest {
+  about "extracts the specified JAR file's MANIFEST file and prints it to stdout"
+  group 'java'
+  param '1: JAR file to extract the MANIFEST from'
+  example 'jar_manifest lib/foo.jar'
+
+  unzip -c $1 META-INF/MANIFEST.MF
+}