Add drawMapOverlay preference

	modified:   res/xml/preference_headers.xml
	modified:   src/de/unierlangen/like/customviews/MapView.java
	modified:   src/de/unierlangen/like/ui/MainYourLocationActivity.java

	modified:   src/de/unierlangen/like/ui/MainYourLocationActivity.java

Conflicts:

	res/xml/preference_headers.xml
Merge branch 'pref' into develop