Added "File a Bug" button

Attempting to address #1182 by adding a "File a Bug" button under the settings/preferences activity.

This spawns a new activity that prompts the user to fill in a title for the bug, the type of bug it is (from a preset list), description of the bug, and how to reproduce the bug. An optional name and email field are there just in case.

These reports appear as ACRA reports, though the stack trace will always read "Report requested by developer" and contain the user provided information in the CUSTOM field under the stack trace. Aside from that, all the other information in an ACRA report is available as normal. I hope that is a good enough distinction between manual bug reports and crashes.

Some screen shots of the bug report form: 

![device-2014-12-23-211915](https://cloud.githubusercontent.com/assets/5815344/5545241/ca7c5e88-8af2-11e4-92ce-8f00480e41be.png)

![device-2014-12-23-211928](https://cloud.githubusercontent.com/assets/5815344/5545246/d44d0278-8af2-11e4-80e4-5c54d05f917d.png)