Modify syntax for arrays of channels

[RobSpringer]

Right now, an array of channels is declared as: chan[COLS][ROWS] F32; and one side of a channel is declared (as a proc member) as: zeroes_out: chan out[COLS] F32;

It may be nicer to have channels as always parameterized entities so we could instead do declarations as: chan<F32>[COLS][ROWS] and as a proc member: zeroes_out: chan<F32>[COLS];

That way we can get rid of the somewhat awkward positioning of arrayness vis-a-vis the in/out qualifiers.