refactor: multiple fixes:

 - add snap-options attribute to pass arbitrary snap.js options on instantiation
 - add snapper.toggle method at runtime
 - publish snapper in the scope to enable method calls from ng-click
 - remove child ng-transclude for snapContent directive
chore: use dist subfolder for builds
chore: Ignore built files
chore: Remove node specific linting options
chore: Add watch task for less files
feature: Allow for 'skinny' shelves and send to back
feature: allow for single shelf without shelves

Also some general tidying up