swarm-lab/Rvision: Rvision 0.6.4

New features New function mimicking Matlab "improfile"" function for measuring pixel values along a line segment. New function for image concatenation. New function for reducing 2D images object to a 1D image (apply-like). New function for tiling/repeating images. Square root, logarithm, exponential, and power functions are now proper generics. Minor improvements and fixes The documentation has been fixed/improved in several places. Minor bug fixes here and there