Update proximity alert with volume adjuster
[wip] Add version check plugin

Currently has issues with auto-reconnection on disconnect.
Add versionCheck warning for earlier LeapJS version
Merge branch 'master' into version-check

Conflicts:
	extras/leap-plugins-0.1.3-extras.min.js
	main/leap-plugins-0.1.3.js
	main/leap-plugins-0.1.3.min.js
Merge pull request #11 from leapmotion/version-check

Version check plugin