Removing unnecessary automattic_url string. Fixes trac #528
Enabling stats for self-hosted sites:

 * API issue was fixed server-side so calls now work for Jetpack sites.
 * Fixed up a few issues with the workflow for signing in to WordPress.com for a Jetpack site to access stats.
 * Fixed #115 by adding infinite scroll support to the media library picker.
Fix for low resolution thumbnails in the media library gridview for WP.com and Jetpack powered blogs. Fixes #118
Fixed the MediaGalleryPickerActivity to work properly when in single select mode:

 * Don't show the contextual action bar when in single select
 * Show the 'Up' button
 * Once an item is tapped, set result IDs and finish the activity.
Jetpack stats: Added support for catching a 403 error, in the case that a user tries to access a Jetpack site with the wrong WordPress.com account. If a 403 happens, the user is prompted to sign in to a different account.
Merge branch 'master' into develop