Jetpack: Ship 3.0-beta3

For changelog, see: https://github.com/Automattic/Jetpack/compare/3.0-beta2...3.0-beta3


git-svn-id: https://plugins.svn.wordpress.org/jetpack/trunk@914281 b8457f37-d9ea-0310-8a92-e5e31aec5664