Replace vars and while loops with tail-recursive functions
Added scalaz as a dependency
Added `toRowMajor` to `Raster`
Raster Spec
Write to PNG directly via BufferedImage, not through a JavaFx image
Remove unneeded import
RasterProjection : Projection from a 2D image to a raster
Added extended comment for RasterProjection
Add comment about anamorphism to RasterRowMajorIterator
Added RasterProjection.pixelBounds and RasterProjection tests
Added SamplePositionGenerator and UniformSamplePositionGenerator
Add RasterProjection.expandByPixels
Add comment to Rect2D.interpolate
Added note about incorrect uniform sample locations
Fixed uniform sampler

Previously, samples were not correctly distributed in a uniform fashion
in image space.  This commit fixes that problem.
Removed comment about sample positions being incorrect
Add definition of SampleFilter
SampleFilter now takes samples from a 2D rectangular region
Make Point2D a trait and implement some point functionality
Implement a box filter