add a toggle method to the slidenav api
Merge branch 'toggle' of git://github.com/infomofo/angular-slidenav.js into infomofo-toggle

Conflicts:
	slidenav.js
Add a $timeout() to toggle

Sometimes the angular digest cycle doesnt trigger so Im adding $timeout
to force it
Merge pull request #2 from sthomp/infomofo-toggle

Add toggle() function