Prohibit lobby nick registration with some previously not-filtered characters between 32 and 127, in particular parentheses.
Use whitelist instead of blacklist, remove dead options and noisy unneeded gui/common/ function.
Still allow existing players with now prohibited characters to login.
This could be enforced in ejabberd too and then the now incomplete JS string can be replaced with a more general one.
Differential Revision: https://code.wildfiregames.com/D715
Refs #4671
Reviewed By: Imarok