vimrc: tune development behaviour

- Match < and > pairs in C++.
- Allow to backspace over auto-indents in Python.
- Do not manually set indentation options. Rely on filetype indent instead.
- remap put command to automatically indent.
- Make * and # command always case-sensitive.
- Don't create *.swp files in project directories (clean git status)
create_symlinks: create ~/.local/var/ directory
bashrc: add history configs
gitconfig: always rebase on new branches

Furthermore, disable by default fast-forwarding when merging.
This makes sure that merged feature branches are still visible in history.