[Fix #543] Do not set tmux destroy-unattached

Signed-off-by: Sorin Ionescu <sorin.ionescu@gmail.com>
Fix git-info added/deleted count formatting typo

Signed-off-by: Sorin Ionescu <sorin.ionescu@gmail.com>
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
Set BROWSER=xdg-open