CYB-236 - Comments - allow people to update their comments

https://jira.ets.berkeley.edu/jira/browse/CYB-236
CYB-238 - Comments - we should send back the whole user object instead of just the name

https://jira.ets.berkeley.edu/jira/browse/CYB-238
CYB-236 - Comments - Fix spelling
Merge pull request #133 from christianv/CYB-236

CYB-236 - Comments - allow people to update their comments