first implementation of L-tilings

[hollma]

cover an L-shaped field with L-shaped tiles

[hollma]

oh, there are some spacing issues:

works only for --dim 32 32 --scale 4 (or some other power of 2 instead of 32), otherwise the pixels are too close or too far apart

[hollma]

made the bug less bad, still not perfect; I do not understand pixel size, spacing, etc. in pictor :-(

[hollma]

fixed

dim/scale = number of pixels (where width = breadth) must be a power of two. Both dim and scale must be multiples of 4.

example:
python core.py -lt --dim 320 320 --scale 20 -b "2" "#ffffff" -op 0.9 -r 32

dim/scale = 16
dim = 5 * 4 * 16
scale = 5 * 4