Reusing old issue: Drop git/github files from python packages

Anyone modify package_for_release.py to skip those files when packing python versions ? probably the scripts folder too

Build scripts need to be revamped - most of it is using outdated code and practices.
Plus, having it streamlined and completely automated allows us to later use it for some interesting things (cough ci servers cough).

• Have gitPython imported AFTER ensuring git is on PATH (see: efdaba2 5ad4f9c).
• Look into replacing py2exe - new issue (Replace py2exe with PyInstaller #491)
• Look into replacing NSIS - new issue (Replacing NSIS #477)
• Update LOOT API to 4.0.2:
  • Create setup.py for LOOT API to make it installable via pip (see: pull-request).
  • Py2exe apparently can't load loot binaries - needs more testing?