Feature/3676 Conduct Polls

refs https://github.com/diaspora/diaspora/issues/3676

**Still in progress**, but I would like to get some feedback. So far I thought the best place to create polls would be directly at the post creation (see screens), so you can add a poll to a post by clicking the poll icon. Any thoughts?
![stream](https://f.cloud.github.com/assets/606519/2449881/dde41016-aeb5-11e3-9e7c-21c59b6db1ef.png)

![stream2](https://f.cloud.github.com/assets/606519/2449880/dde2b2fc-aeb5-11e3-81fc-b4a54fa65e3e.png)