JMonkeyApplication cleanup
-> Do not use Vuforia callback
-> Toggle spatials when board not tracked
Merge branch 'master' of https://github.com/forkch/scrabble_ar

Conflicts:
	ArScrabble/app/src/main/java/ch/zuehlke/arscrabble/jmonkey/JMonkeyApplication.java
Merge branch 'master' of https://github.com/forkch/scrabble_ar
Merge branch 'master' of https://github.com/forkch/scrabble_ar
Add all mtl and obj files