Finished fs2mod implementation. Reorganized the code a bit.

Implemented support for multiple sources. (Might need some work)
Accidentially removed code which is still needed.
Added "version" file in fs2mod archives. Read version string from this file.
Fix an issue with the directory picker.
Merge pull request #1 from Nepenthes/develop

Added support for "version" file in fs2mod archives.
Experimenting with fs2:// and improving support for version fields.
Fixes...
Fixed checking paths... Thanks to Hellzed for finding this!
Allow the use of fso:// as well.
Hopefully fixed the bug for niffiwan now.
Further PyQt4/PySide compatibility fixes.
Python 2/3 compatibility enhanced.
Fixed issue with progress bars.
Fix for special characters and whitespace in fso:// links.
Added reset selection.
Merge pull request #1 from ngld/develop

Rebase
Unity Launcher integration
Adds a quicklist and a progress bar on the Unity launcher icon. Needs fs2mod-py.desktop to work.
Fix #2
Protocol scheme installation, now for Linux
The protocol installation button should now also appear on Linux, and be able to create the desktop file and add the mime type.
Merge branch 'develop' of https://github.com/Nepenthes/fs2mod-py into develop