Feature: gap, colGap, rowGap

[Daniil Pankov]

I think it shouldn't be hard to add gap, rowGap, coulmnGap
It will greatly increase the speed when building blocks with same spacing between elements. I tried patching by myself, but it was a bit harder, than I thought, thanks :)

Right now I have to do:

<View style={{ columnGap: 16, ...styles(...) }}>