- add Python 3 support
- code cleanup
Merge remote-tracking branch 'main/master' into merge

Conflicts:
	static_precompiler/management/commands/static_precompiler_watch.py
	static_precompiler/templatetags/base.py
	static_precompiler/tests/test_base_compiler.py
	static_precompiler/tests/test_url_converter.py
	static_precompiler/utils.py
bugfixes