Bumped version number to 3.7.2-SNAPSHOT
updated histroy
updated .gitignore
Fixes for ES5 strict mode
fixed keycharm issue
Merge remote-tracking branch 'origin/develop' into develop

Conflicts:
	dist/vis.js
updated build
fixed keycharm with strict mode
Merge branch 'master' into develop
removed double code
Merge remote-tracking branch 'origin/develop' into develop
fixed zooming on tablet
- Sidestepped double touch event from hammer (ugly.. but functional) causing strange behaviour in manipulation mode
- Better cleanup after reconnecting edges in manipulation mode
redraw on back on manipulation
added two 'var' statements to comply with use strict
Merge branch 'master' into develop
Merge branch 'master' into develop
fixed infinite loop when clearing dataset
Removed unused dependency `wrench`
Fixed groups not being filtered after setOptions