Emulate a Powerline setup. Includes:
* Change custom foreground colours to background colours
* Add 8 different separators, selected randomly based on terminal ID
* Prettier and more sensible Git repo sigils
* Cleaned and condensed code
Alias 'cd' to create a flag.
Detect flag during prompt script.
If directory changed to the root of a git repository, print 'onefetch'
Remove flag if set.