Cache ng templates

- [x] see http://www.codelord.net/2013/06/16/optimizing-angular-templates-with-grunt-on-heroku/?goback=%2Egde_4896676_member_252341368/
- [x] learn about `$templateCache`
- [x] cache templates
- [x] reorganize templates directory
- [x] copy all html files except angular templates