First Git commit.

* Moved sp.py to ../packages/source-python/__init__.py to make it clear that it should never be imported from.

* Changed CEdict.get_prop(<prop>).get_<type>() and CEdict.get_prop(<prop>).set_<type>(<value>) to CEdict.get_prop_<type>(<prop>) and CEdict.set_prop_<type>(<prop>, <value>)

* Added .gitignore file to replace the .hgignore file. Added many unneeded Python3 packages to the .gitignore file.