Made robot afterimages declare themselves as air blocks and made robots ignore afterimages when moving, to avoid potential issues when for some reason they were not properly cleaned up (e.g. on chunk borders after world loads). Might help with #440.
Merge branch 'master' of github.com:MightyPirates/OpenComputers into master-MC1.7.10

Conflicts:
	src/main/scala/li/cil/oc/common/block/Delegate.scala
	src/main/scala/li/cil/oc/common/block/Delegator.scala
	src/main/scala/li/cil/oc/common/block/RobotAfterimage.scala
	src/main/scala/li/cil/oc/common/tileentity/Robot.scala