fixed multi selections, merged conflict, additional layout improvements

1. Added drawables and selectors for proper multi-selecting entries in the listview. Therefore had to do something for the distinguishing of _next wednesday_ and _currently selected_ as both use(d) `holo_dark_blue`. Hence I currently switched the _next wednesday_ entry to `holo_dark_green`. That's because user expect a blue selecting of entries as it is default in Android.
2. Got a merge conflict with some files due to changes in indention. Fixed it.
3. Further improvements on the tablet layout and some minor quirks on the phone layout. Now the tablet layout features a light contrast color on the borders to fix the sight of the user on the center.