Info Panel Replacement

Splits the "Default Programs" Panel into two separate panels:
- System Info
- Applications & Removable Media

Moved everything from c to python, cleaning a lot in the process.

There seems to have been some kind of update method that I've never seen in action.
I didn't port that one, seems to be dead code (or I don't know how to show it)

I removed the ability to rename the device from the System Info panel, as it would not work in cinnamon-settings anyway, except if it was started as SU.
If you want this back, I guess we need something similar to the user panel "unlock" button.