Allow third-party plugins and addons to override any CampTix e-mail with a filter.


git-svn-id: https://plugins.svn.wordpress.org/camptix/trunk@786381 b8457f37-d9ea-0310-8a92-e5e31aec5664
Use .get instead of .getByCid which was removed from collections in Backbone 0.9.9


git-svn-id: https://plugins.svn.wordpress.org/camptix/trunk@786386 b8457f37-d9ea-0310-8a92-e5e31aec5664