Jetpack: Bump to 3.0-beta2

See: https://github.com/Automattic/Jetpack/compare/3.0-beta1...3.0-beta2 for full changelog.


git-svn-id: https://plugins.svn.wordpress.org/jetpack/trunk@912824 b8457f37-d9ea-0310-8a92-e5e31aec5664