Add sentry integration module

Module for enabling raven initializing to report to sentry.

Based on feedback from my presentation at odoo days 2014

Todo
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- [ ] Add git module version overwrite to raven
- [ ] Overwrite the except_orm message pop-up with something a little more friendly to the user
The reasoning behind that was to never have sentry cause exceptions.

In the event that you have the module installed, but for some reason or another, one of the python dependencies disappears or causes an error, we don't want sentry itself to start causing crashes.