Added like button
Added like model
Added like_count method
Made fields unique together
Added does_like method
Created like toggle view
Added test to make sure logged out user can not like a comment
Added tests for comment like security
Added tests to verify like view functionality
Added check if user should see the like button
Added template tag to like or unlike a comment
Split code up for later javascript
Added javascript for comment likes
Added code to allow user to click the like button
Added text next to comments that are liked
Merge branch 'like_button' into develop