[FEATURE] - Support for OpenRC/generic, non-systemD

[tlhonmey]

With Remotely, I could run the installer on OpenRC systems and then just write my own init scripts.

With ControlR, the installer crashes as soon as it can't find systemctl and the client doesn't seem to get set up properly.

Having it print a warning about lack of init support, but then continue setting up the rest so it can be launched manually would be a sufficient start.

From there I can probably assist with creating the actual init scripts for whichever additional init systems seem worthwhile.