benchmark + small optimization
scaliform
new raster
new Raster: IntARGBRaster replaced by ARGBRaster that uses Byte.
added channelSize
faster rasters (specialized for Byte data model)
Merge branch 'master' of https://github.com/sksamuel/scrimage into rasterExp
max channel value for color model
Merge pull request #53 from gwenzek/rasterExp

Experimentation on rasters