Tito 0.6.13

This release provides features and fixes that were submitted from community members a while ago. We finally managed to merge these changes:

• Modernize developer installation
• Make get_project_name more resilient
• Allow including macros through SourceX
• Fix some PEP8 errors and tests
• Fix Source0 and %prep phase in tito.spec
• Drop python-blessings dependency and move to python-blessed
• Rename HACKING to HACKING.md so it renders on GitHub

Thank you @tjanez, @ernestask, @evgeni, @dhilst and @FrostyX for contributing to this release.