Adding option to save and load state by timestamp

Load by timestamp: load last state is expanded from 1 to 8 actions, for newest to oldest state

Save by timestamp: overwrite the oldest state (or use an empty slot if available)

Adding remaining hardcoded state keys to hotkey dialog

Adding a program exit hotkey
Merge remote-tracking branch 'John-Peterson/state'
Added Dance Mat support for the Family Trainer/Active Life series.

Select the dance mat via Configure > Gamecube > Port 1 > Dance Mat

The dance mat is mapped to the GC Pad:

D-Pad Up = Blue Arrow Up
D-Pad Down = Blue Arrow Down
D-Pad Left = Blue Arrow Left
D-Pad Right = Blue Square
Y Button = Orange Arrow Up
A Button = Orange Arrow Down
X Button = Orange Arrow Right
B Button = Oranage Square