Contacts: fix UI glitches

http://code.google.com/p/cyanogenmod/issues/detail?id=3596

1. Missing space after number-label.
Fixed with margin

2. Group icon is not centered verticaly.

3. Number-label was flickering on redraw.
Was due to android:ellipsize, but as the number-label should never
be as long as the screen (even on my ldpi), this should be okay.

Change-Id: I58191ccce65924b72fd749118766784e702bbf5c