Adds a simple regex based filter to the game list.

Adds cah.GameList methods for creating and applying the filter, as well as a filter text input element next to the create game button. Filtering is bound to the input keydown and game list update.

It's a bit of a superfluous feature, but it saves me a lot of time (when I apply it dynamically) over Ctrl-F the name of the game (which then often changes position in the game list before I can click join).