Added some additional angular snippets and changed the existing ones
to use the annotated syntax which supports minifications, see:
https://docs.angularjs.org/tutorial/step_05 (A note on minification).
Also added some variants that auto-insert the scope, which is commonly
done.
Merge pull request #467 from craigp/angular_minification_fix_plus_additional

Added some additional angular snippets and changed the existing ones