Issue #171

server limit the number of webUI clients that can attach.

This will probably always be "0" or "unlimited", but allows ops to set a max limit for WebUI clients. (realistically, probably 3 is more than enough)

@crankycoder r?
@pdehaan: SEE!? That's what happens when you tweak my minor OCD. 

Still, good call, I've normalized the config names and allowed the old names for temp compatibility. I'll drop those once things have been fixed up in all the old configs.