Removed case sensitivity when parsing chat commands

I believe this should remove the case sensitivity from the chat commands, thus
/guest == /GUEST == /GuEsT etc...
When using help, as best I can tell /help CoMManD will give the correct help but show the usage as /CoMManD (i.e. mirroring the user input).
For a simple /help the commands might all be shown as lowercase, I can't quite tell, but from how they're used as keys in the commandlist it'll mean bigger changes to implement this whilst maintaining the camelCase for /help.