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
You can also add a Constructor that doesn't take a width and a height so use is more intuitive with [``override()``][1], you can mimic the code or extend [``SimpleTarget``][2].

[1]: http://bumptech.github.io/glide/javadocs/340/com/bumptech/glide/DrawableRequestBuilder.html#override(int, int)
[2]: https://github.com/bumptech/glide/blob/master/library/src/main/java/com/bumptech/glide/request/target/SimpleTarget.java#L61