Fix touch zooming while zoom animation is playing. Fixes #1591 #1571
Better fixes for touchzoom while zooming. If we got a touchmove and touchend in series before the animation frame for the touchmove fired then we'd get into a broken state.
Update TouchZoomEmu with more crazy tests. Useful when debugging touch zoom behaviour
Fix up brace position
Merge pull request #1594 from danzel/zoom-fixes

Fix touch zooming while zoom animation is playing. Fixes #1591 #1571