Update Splunk Artifact Repository with Java SDK 1.2.0

##Changes
+ Added deploy script and its documentation file, deploy.md.
+ Modified build.xml so that it produces the customary maven/ivy/gradle artifacts: binary, javadoc, and sources jars.
+ Updated github wiki with instructions on installing/configuring maven and deploying to the repository when publishing a release.

##Tested locally and on our new staging repository
It is at http://stg-artifactory:8081/artifactory/devplat-staging/. DNoble can provide the username/password.

Signed-off-by: David Noble <dnoble@splunk.com>