[#83211730] Fixing TeamSnap event webhooks.

- Fixed an issue where adding a group to an existing event would not trigger the correct actions.
- Fixed an issue where multiple events would be created for a unique event, if a game was made with more than one competitor.
- Fixed an issue where the response was not being decoded correctly after sending an initial request to TeamSnap for a game event with competitors.
- Moved group check to TeamSnap webhook template and added check to each unique webhooks `process()`
- Fixed typos in comments

Requires: https://github.com/AllPlayers/allplayers-mainline/pull/4118
The diff preview doesn't show my issue well, but peep this. 
![2014-11-24_1100](https://cloud.githubusercontent.com/assets/2251119/5169035/54b750b2-73c9-11e4-98b8-a041aa6d9ace.png)
There isn't actually any logic there any more.