Fix setting the 'pac' alias
[Fix #535] Set Pacman frontend to 'pacman' when none set
Add `custom` folder plus scripts and aliases.
Activate custom scripts and customise `.zshrc`
Add `prompt_jakob_setup` file and activate prompt.
Customise `zshenv`.
Customise `zpreztorc`.
Update alias definitions.
Update alias definitions.
Enhance aliases.
Enhance zshrc to be used on other boxes as well.
Enhance zshr (add if checks for named dirs etc)
Enhance aliases
Small change to prompt_jakob_setup.
Update alias definitions.
Tidy up aliases (remove lots of systemd aliases)
Add dfc alias
Add proper arguments to df alias.