ManageWP.org sharing for Jetpack free WordPress plugin

Extends the Jetpack plugin and allows you to add a ManageWP.org sharing button to the list of sharing services available under Settings > Sharing in your dashboard. Important: for this plugin to work, you must activate Jetpack first, and activate the Sharing module. This plugin is a work in progress. You can report issues here, or submit a pull request on GitHub. Kudos to Jeff who gave me the idea for this plugin (#)!