Login to create or post

* Changed controllers to redirect to appropriate location when not logged in and trying to perform CRUD actions on a question or answer.  

* Controller also associates answer and questions with current user upon creation now.  Also added flashes to controllers.  

* Tag testing is now integrated with question testing to DRY out code.


### Page response to manually redirecting to new_question_url when not logged in

![screen shot 2013-08-30 at 10 45 43 am](https://f.cloud.github.com/assets/4422080/1058592/4fbdc2cc-118b-11e3-9edb-03c63652fe5d.png)

### Page response to trying to create answer to a question when not logged in

![screen shot 2013-08-30 at 10 49 21 am](https://f.cloud.github.com/assets/4422080/1058619/c87fcf20-118b-11e3-9744-36be0524ef3d.png)