Adds support for displaying inline images within content blocks.

Makes use of `WPImageGetter` to load the images in ImageSpans.
Added image spans directly instead of using Html.fromHtml().

This allows for other block actions like linking to still work. I had to limit the image size to 240dp, otherwise the images would load blank white.
Moved `imageGetter` creation outside of the media loop.
Merge branch 'develop' into issue/1835-notifications-inline-images
Removed unused import.
Matched up span exclusion types.
put signOut in an AsyncTask and show a ProgressDialog
use the asyncSignOut in WPActionBarActivity
use the asyncSignOut in PreferencesActivity
`NotificationsDetailListFragment` now listens for note changes.

List will refresh if the currently viewed note was changed. Detail view will pop back to list if the note was removed.

Also added a note changed listener, so that `CommentDetailFragment` can be notified when the note changes and update the comment and moderation buttons.
Added a null check on `getActivity()`
Add a newline to accommodate additional images in the content.
Merge pull request #1893 from wordpress-mobile/issue/1890-notification-detail-changes

`NotificationsDetailListFragment` now listens for note changes.
don't send BROADCAST_ACTION_SIGNOUT from removeWpComUserRelatedData()
null check mProgressDialog before dismiss and use local context instead of getContext
Merge pull request #1895 from wordpress-mobile/issue/1796-signout-lag

fix #1796 signout lag
Added context null check to reader service, WelcomeFragmentSignIn now uses the application context when starting the service.
Merge pull request #1902 from wordpress-mobile/issue/1898-npe-reader-service

issue/1898-npe-reader-service
fix #1897: null check mBucket onResume/onPause
Call onBlogChanged when there are blogs visible in the app