Makefile

This PR addresses #11 by adding a Makefile to generate the .py file from the .ui files. As a separate commit, it removes the auto-generated code to help prevent the two getting out of sync (this means users wishing to download and run the code must have pyside-uic installed). In the longer term a setup.py file that does this as part of build_py might be a better idea.

Note that the makefile does not insert a licence header into the generated code.