Update to use filtering of child mouse and touch events.

Removing obsolete TOUCH_EVENT_WORKAROUND code and instead implement
use of of childMouseEventFilter inside QDeclarativeGeoMap. This allows
for MapMouseArea to be used together with MapGestureArea with minimal
problems.

Change-Id: I2eeaedc4881688fda4dede663f97fb0a482f14c3
Reviewed-by: Aaron McCarthy <mccarthy.aaron@gmail.com>