Merge pull request #13 from froehr/feature/MotionGesture

added Feature/motion gesture
fixed actionbar support for devices < v21, improved design (nav drawer, buttons) and added necessary icons
Merge remote-tracking branch 'origin/map-design' into develop

Conflicts:
	app/src/main/java/de/ifgi/igiapp/igi_app/MapsActivity.java
	app/src/main/res/layout/activity_maps.xml

- adjusted button alignments
Adjusted button for GestureRecognition. Needs to be fixed yet.
Merge remote-tracking branch 'origin/develop' into feature/MotionGesture
Adjusted Button