Hook up Cesium and Leap Motion Controller.
Merge branch 'master' into leap

Conflicts:
	src/app.js
Merge branch 'master' into leap
Prevent globe from disappearing.
Add zoom.
Enable gestures. Add pick gesture.
Merge branch 'master' into leap
Do nothing if a hand is not detected.
Enable gestures the right way.
Merge branch 'master' into leap

Conflicts:
	src/app.js
Merge branch 'master' into leap

Conflicts:
	src/app.js
Merge branch 'master' into leap
Use Cesium's update loop instead of the Leap's.
Add query parameter.
Merge branch 'master' into leap