speedup the large worlds of Koch
give the pseudo code of the general case for the first recursive trees
speedup the large sierpinski worlds
mouse coordinates should be consistently in black
loosen the slope equality test, and display slope in debug mode
don't do lame tests, and don't fail either
let the details area grow to take any additional space
also merge lines that have the same end, not only the same start
detect when lines are included one within the other with no common extremities

Fix #381