Windows compatibility fixes
Changed block size from 24x24x1 to 32x16x1 to work on GTX 260
Add '.yml' to file name if not specified, for convenience
Set block size to (16,16) in `add_vec_to_mat`
Use ceil_div for ceiling division
Fixed block size in kernels; switched to 'square' 16x16x1 blocks
Factor add_vec_to_mat block size into variable
Merge branch 'Wainberg-master'