Draft of designspace file format specification.

This draft is expected to change.
Small tweaks.
Typo
Designspace format work

More work on the designspace document format. Plus one bug in the
documentReader.
Remove executable bit from files that don't need it
Merge pull request #1 from rrthomas/master

Remove executable bit from files that don't need it
Add setup.py script
Merge pull request #2 from khaledhosny/master

Add setup.py script