Zoom/rotate/tilt gestures re-use center of action
Zoom/rotate/tilt gestures re-use center of action

This allows a single touch zoom gesture immediately followed by an
azimuth or tilt rotation (or vice-versa) to share the same center
of action. This makes the behavior for single touch gestures
consistent with how the center of action is handled for multitouch
gestures.

jstrait/webgl-city,jstrait/webgl-city