Redesign of the bug report dialog

- Add title to dialog
- Replace tab with space in version area
- Fix overlapping words in link section
- Reformat version area

Before:
![before](https://cloud.githubusercontent.com/assets/488530/3570995/ff740642-0b57-11e4-9489-577f3fea928e.png)

After:
![after](https://cloud.githubusercontent.com/assets/488530/3570997/029a05a6-0b58-11e4-802e-a1c5a2ed32c5.png)