Add poll content type

[davemcg3]

Polls should be able to be included alone or as part of a resource that can potentially include all other content types.

AC:
User should be able to add a poll alone or as part of text.
Results of the poll should be stored in the db.
Polls should have a question.
Polls should have 2-4 options, configurable by the user.
Polls should be commentable.
Polls should be reactable.