Slight Changes to Nav Drawer

- Moved the donate button the bottom, it's not like anyone has used it anyways...
- Changed "Powered by PkRSS" to "Extras" and the link to it
- Created an About Button
Preparing AboutFragment

I kinda like this layout. I'll improve upon rather than going with my other idea. Now, if only I could add footers to this GridView... I could put the libraries and dev credits here too. I don't wanna put them with the header. :/
Stuff

I haven't really submitted a commit in a while so I kinda let it all
become a big one...

Noteable differences:
- Experimental/Newer libraries
- Repackaged Okio/OkHttp for Android L (Temporary)
- Feed tag fixes
- More hardcoded authors
- More About Info
- More raw resources
- Refresh icon in feed actions
- Fancy progress library