Minor improvement to SignaledType

Allows using non-void functions as callbacks, as originally intended.
Fix assert caused by misuse of ScriptTeleportRequest message block data

Thanks to Nomade and Esmeralda for catching this one!
Fix SignaledType not compiling on Windows
Correct a typo: AntiSpamNotFriends should be AntiSpamNotFriend
Fix creating dummy ui warning on the login panel

Part of my ongoing work to fix enter not working on the login screen
Fix Tobi Genesis' issue of the console sitting over the login fields after a failed login when hiding login screens.
Eep, this escaped the dummy ui warning commit yesterday.
Fix focusing marked via the radar menu not working
Merge remote-tracking branch 'Liru/master'
update spanish translation: fix in panel_login.xml file