refactoring: moved code to src/pypolibox
added main() cli to pypolibox.py
moved database and grammar into subdirs of src/pypolibox
load_settings() can now handle all kinds of path vodoo
fixed parameters of check_and_realize_textplan()
database.py now works, if imported as a module
updated gitignore
realization.py can now be imported, doesn't need load_settings()
removed load_settings() altogether
updated readme (no config files needed. added $PATH example)
added setup.py, NEWS.rst and MANIFEST.in
updated installation instructions
added classifiers to setup.py
updated documentation generation
fixed path in html generation documentation
	TODO.txt