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
Fix possible NPE in FacadeItemRenderer
Fix canFill/canDrain in tanks
Update EntityRobotPicker.java

Prevents a crash if the pipe a robot is docked onto is broken.
Merge pull request #1835 from viliml/patch-1

Update EntityRobotPicker.java
Merge pull request #1831 from Prototik/npe-item-facade

Fix possible NPE in FacadeItemRenderer
added handling of blueprints without unique ids, close #1842
Merge pull request #1833 from Prototik/tank-drain

Fix canFill/canDrain in tanks
started to work on tester item
started to work on tester item
Merge branch '6.0.x' into 6.1.x

Conflicts:
	common/buildcraft/transport/render/FacadeItemRenderer.java
Merge branch '6.1.x' of github.com:BuildCraft/BuildCraft into 6.1.x
Merge branch '6.1.x' into 6.1.x-pathfinding
made progress for implementation of testing framework, #1846