Add support or channel delay

[fmalcher]

// master left
SETD^m.delayL^0.02

// master right
SETD^m.delayR^0.5

// input
SETD^i.2.delay^0.02

// line input
SETD^l.0.delay^0.2

// aux output
SETD^a.3.delay^0.3

All delays maximum of 500 ms