Friendlist UI

Fixes and updates:
- add viewholder
- add highlight color
- add SwipeRefreshLayout with spam protection (disable the multiple sync requests at once)

Dropped:
- friend since support
- online indicator that was broken in all the translations except the default one

Design based on android L Listview keylines.
Note: the images aren't round!
Note 2: the this design is based on a listview but is applied on a gridview.
http://material-design.storage.googleapis.com/images/components-keylinesinlists-3_large_mdpi.png

![screenshot_2014-08-24-16-47-36](https://cloud.githubusercontent.com/assets/5322473/4023647/38d012bc-2b9e-11e4-9589-9180ba7bbe0a.png)