Game lobby extra panel improvements

PlayerExtraOptionsPanel is now once again XNAPanel instead of XNAWindow. What this means is that PlayerExtraOptionsPanel.ini is no longer read and the controls can now be customized in game lobby INIs (prefixed with PlayerExtraOptionsPanel_) and can use the dynamic properties from INItializableWindow as well. For a quick migration, can simply port the contents of PlayerExtraOptionsPanel.ini (if any) to GameLobbyBase.ini and prefix any PlayerExtraOptionsPanel child controls with PlayerExtraOptionsPanel_.
It is now possible to set $ToggleableControl on XNAClientButton & derivatives that are children of INItializableWindow. What this does is make the button toggle visibility of said control. Only restrictions are that it won't work on the parent window itself and the target control must be fully initialized before the button (e.g the button or its parent(s) must be defined after the target or its parent(s) in the children list of [GameLobbyBase] or any other game lobby window control). Main use case would be additional panels for game options to conserve space where needed.

CnCNet / xna-cncnet-client