Use the pythonrc Python startup script added as a submodule instead of
fiddling around with a script to build a (not really working) version
for myself.

post-merge.
- Moved direnv to .bashrc, it shouldn't have been in .bash_completion.d
to begin with.
- Added a copy of pythonrc.py (from
https://github.com/lonetwin/pythonrc/).
- Generate Python startup script.
- Output during post-merge to stderr.

less portable than customizing the prompt myself.
- Symlink the TravisCI Bash completion to the one generated by the
travis gem inside .bash_completion.d, remove specific source in .bashrc.
- Moved AWS CLI completion to file inside .bash_completion.d.
- Removed some unused blocks in .bashrc.

Git configuration.
- Don't ignore all files, but set status.showUntrackedFiles to no, add
to post-merge hook.

- Moved pkgs Ansible playbook and Dropbox autostart to new ansible-desktop-playbooks Git repo, added said repo as submodule.