Enhanced flowdock notifier

Reworked the Flowdock notifier to use the new upcoming Flowdock threads api and have more Flowdock-style notifications. This will produce deployment threads that contain all the events and state from a single deployment. It will also notify the orignal chat thread so that context is not lost. Some screenshots:

First it will create a new thread in inbox that looks like this (of course in the beginning it will only have the "Started.." activity and the status will be a yellow "pending"):
![screenshot 2014-10-28 15 17 59](https://cloud.githubusercontent.com/assets/299596/4808873/e4d45408-5ea5-11e4-8365-c74880f9ac5d.png)

Then it notifies the deployer with a link to the thread (last message, blurred the url):
![screenshot 2014-10-28 15 17 45](https://cloud.githubusercontent.com/assets/299596/4808874/e4d4d89c-5ea5-11e4-9533-938d57095cd6.png)

The full deployment thread looks like this (opened from the link or the inbox activities):
![screenshot 2014-10-28 15 18 14](https://cloud.githubusercontent.com/assets/299596/4808872/e4cfac64-5ea5-11e4-9472-f17fba03eaf1.png)
It has urls to all the relevant places (repo / branch etc) and allows discussion in between and after the deployment activities.

Note: We have not yet enabled the new api in production, but it should be out this week.