Archiver GUI

CEFPython requires Python 3.2, unless you build it from source yourself
which isn't guaranteed to work with later versions anyway. So everything
is now run in 3.2, meaning no more LZMA(.lz/.xz) support for now.
Instead, we now have a custom exception for file extension issues, such
as missing or incompatible extensions. The beginnings of a cleanup of
structure may or may not be present too. Baby steps.