v0.16.0

PyPI pre-release

New features:
- installable via pip

Changes:
- new name: git-viewer
  because another project has already been uploaded with the name gitu by now
  commit af905ea92dce02a6c1a966b089458a1545424cf5
- new license: 0BSD
  because PyPI does not support WTFPL
  commit 1814123c1c4a0516852030bdf72cf856a61695e5
- new directory structure
  as PyPI wants to have it
  commit 37a8c47ae337599b83c81cb32e1bef0ed6fb6823
- the code is not directly executable anymore
  instead it must be installed as a package and then that package can be executed
  commit 565be0c7007501b5b40d433dad4f425d7c841e47

Known bugs:
- pip ignores requirements.txt
  i.e. the dependencies still need to be installed manually