added a print.out question : why will an agent not move, once he reach it's destination? May he have to move for passing

updated tests after failing

Added load and save to env (left GridTransitionMap load and save for now)

new generators that take agents_handles as extra input and return the agent's initial position, direction and target

add cell_neighbours_valid, is_cell_valid to transition_map
add invalid cell detection to editor and rendertools

updated curve detection. There might be a bug in nbit calculation for levels generated using the editor notebook