Create a .Delay() API #158

This can be a delay library separate from SB.
It should allow support for both widget and gadget delay mechanisms:

• Delay(Update) - time based
• Delay$Callin, such as DelayGameFrame, DelayUnitKilled, and so on

WG.Delay.Delay(callin[, time])
WG.Delay.DelayGameFrame(callin[, gameFrames])
GG.Delay.DelayUnitKilled(callin[, callinInvocations])