Made the drawer more attractive and easier to click on items
Fixed bugs

fixed crash when changing orientation. Was due to mStationsFragment in MainActivity becoming invalid during the orientation change.

stationsFragment now saves which state is selected.

When selecting the state from the graph, the stations list is shown correctly, and there is no more back stack confusion.
Merge pull request #12 from feerrenrut/rt_improveDrawer

Improve and fix bugs with drawer