started A* algoritm
initial attempt at pathfinding algorithm
added management of blocking blocks
fixes in the pathfinding system
initiated a test framework
Merge branch '6.1.x' into 6.1.x-pathfinding
progress in path finding algorithm
started to work on tester item
started to work on tester item
Merge branch '6.1.x' into 6.1.x-pathfinding
made progress for implementation of testing framework, #1846