Make GERTiMNC and GERTiClient services

[JakobCh]

So they can easily be managed with rc GERTiMNC start/stop
This also provides autostart

Heres an example I made from GERTiMNC.lua, place it in /etc/rc.d/ and run rc GERTiMNC enable to have it autostart. (You still have to type rc right now after boot, it seams GERTiMNC doesn't like being run by the first rc pass at boot)

GERTiMNC.txt

[MajorGeneralRelativity]

As discussed on Discord, I will look into this. Autorun functionality can be achieved with one line in an autorun.lua right now, which is a partial issue cover.

[MajorGeneralRelativity]

GERTiClient would not be possible to rework for RC functionality without a major refactor. However, GERTiMNC is possible and has been included.