syncdevice.py: Changed format of the file which specifies what to sync.

So it now looks like a recursive directory tree:
Music/
    SomeArtist
    SomeOtherPerson
Pictures/
    Stuff/

It looks at the relative indentation to determine whether to prepend
the last directory name to the current entry.
syncdevice.py: Uses -dumbtty option for unison so terminal doesn't get confused if you ^C it.
syncdevice.py: Made code prettier.