Minimal semi-working skeleton package

No tests yet
Begin refactoring (new files, dirs)
Refactored & minimally working

* Installed to user-site with pip
* Commands correctly dispatch to `calabash` and `saxon`; however, although the subprocess is correctly called, it always seems to fail (while attempting to retrieve the fallback document from the web; haven't yet tested with local xproject files)
Added .gitignore (from GitHub’s Python-flavored ignores)
Fixed url in `setup.py`
Added encoding comments