added Java7u21 RCE module

Click2Play bypass doesn't seem to work anymore.
Make fixes proposed by review and clean
Delete project files
Fix also ruby module
Explain Ranking
Merge pull request #2 from jvazquez-r7/provider_skeleton_clean

provider_skeleton Exploit Clean and Fixes
Land #2011, @matthiaskaiser's exploit for cve-2013-2460