german translation update
add QScintilla2 to INSTALL
can re-center when scaling mapCanvas extent
new map tool to select single feature
add mapCanvas and messageBar to attribute editor context
use a specific class for the widget (to be used as a custom widget), rename old _widget to _wrapper
can select related feature on the map from the relation reference widget (in the attribute form)
also makes attribute form non modal
temp fix crash
separate highlight and open form icons, deactivate highlight button when not needed