Issue test button

This will add the possibility to submit personal test results for an issue.

![issue-test-button-1](https://cloud.githubusercontent.com/assets/33978/3478104/8a64e290-032d-11e4-8abc-38a6795b4e7c.png)

The total will be displayed in the issue item view:

![issue-test-button-3](https://cloud.githubusercontent.com/assets/33978/3547345/fe98b3e6-0894-11e4-8888-e1055f5f7801.png)