Have animation frames not be trigged when not receiving device frames

Note that prior to this, every animation f
Fixes #159 unable to background after disconnect and reconnect.

Note that this simply adds a cleanup line to connection/base.js.  An
alternative and perhaps more proper way of fixing this would be to
destroy the entire connection object on disconnect, and create on
connect.
Fixes #158 setBackground unavailable; add an option controller.loopWhileDisconnected
Merge pull request #157 from leapmotion/requestAnimationFrame

[wip] Have animation frames not be trigged when not receiving device frames
Fix code style for default opts.useAllPlugins
Release v0.4.3
Fix issue where Leap.loop would ignore useAllPlugins option
Use grunt to build scripts.  Fixes 141

changing the version in package.json will now update bower, the header
comments, version.js, the src file names, and all the places those src
files are used.  The banner is now automatically included at the tops
of script files. yay.  Still need to go through and clean out the
makefile, but that can be done later.
Add grunt watch
Fix browserify ignore
Add load-grunt-tasks
Downgrade uglify to support node 0.8.0
Add Grunt task for running tests
Downgrade load-grunt-tasks for node 0.8 support
Merge pull request #161 from leapmotion/grunt

Use grunt to build scripts.  Fixes 141
Update version number in test/helpers/browser.html
Travis config to use grunt
Merge pull request #163 from leapmotion/grunt

Travis config to use grunt
Merge branch 'master' into 0.5.0

Conflicts:
	CHANGELOG.md
	bower.json
	examples/dumper.html
	leap-0.4.3.js
	leap.min.js
	lib/_header.js
	lib/version.js
	package.json