Make reaction take a direct foreign key to WallPosts.
Add Ben Konrath as a copyright holder.
Properly deal with DRF2 style related relations in the Ember Data adapter.

This means we're switching to identifying records by the lowercase model name
whether we're using the pk or the slug as the id.
changes after review
wip
Merge pull request #215 from benkonrath/wallpost-reactions-non-generic

Wallpost reactions non generic
Merge branch 'master' into ember-multiple-transactions
wip