Add the option to allow grid input

[Reptorian1125]

Hi,

There are a couple of effects that utilize a grid input. If we could have the option to have floatgrid(w,h,[default value...],min,max) and intgrid(w,h,[default values...],min,max), there is a few more effects that could be easily accessible. There could be even boolgrid(w,h,[default bool]). And colorgrid(w,h,3/4 channels,[colors list]).

On [default values..]. This is just collection of w*h values that are assigned by default.