Strip out the old setup and post setup stuff from this repo

[philwareham]

Prior to having our own repo of FluxBB customisations - we had a patch script and setup process. However as customisations grew this became unfeasible to maintain.

Just a NTS to salvage the important bits from the older setup routine and move to our custom Flux repo. Just leaving this repo as the theme stuff only (also simplifies the build script too).