RemoteViewsTarget feature requested on #242

Ability to load a bitmap into an ImageView of a Widget using
RemoteViews.

Example of usage on the following gist
https://gist.github.com/pavlospt/00242d5102ac8f76e169
I can add a functionality for Notifications too. Will try and push it later on the evening. Then we can make one generic and have 2 separate classes for Widget and Notifications.