Style fixes
Fix overlay chat lines expiration

It wasn't working right when the widget was hidden because it
wasn't receiving any Ticks. Instead of counting, we're now using
Game.LocalTick as the tick source.
Fix scroll offsets

This is not a full fix, it merely restores the functionality
already present. The ScrollPanelWidget does not work right if
Align is set to Bottom but ScrollToBottom() isn't called after
adding items and there's not enough content to scroll.
Awesome faster & smooth scrolling

Try the credits or the "Random map" button.