Utilizes the event system (which is what should have been done here
initially), in order to prevent coupling between two different window frames.
This also makes booting games more versatile using the UI event system,
as the event can just act as a carrier for the filename, making directly
calling boot functions unnecessary. All that's needed is for the event to
propagate to the frame.
* Focus "Hash Code" / "IP address" text box by default in "Connect"
* Focus game list in "Host" tab
* RETURN keypress now host/join depending on selected tab
* Remember last hosted game
* Remove PanicAlertT:
* Simply log message to netplay window
* Remove them when they are useless
* Show some netplay message in OSD
* Chat messages
* Pad buffer changes
* Desync alerts
* Stop the game consistently when another player disconnects / crashes
* Prettify chat textbox
* Log netplay ping to OSD
Join scenario:
* Copy netplay code
* Open netplay
* Paste code
* Press enter
Host scenario:
* Open netplay
* Go to host tab
* Press enter
