a comment
merge mainline
Revert "merge mainline"

This reverts commit 4de1515252035760970c6a296c72b84831beb583.
fixing checking negative state logic.
Remove redundant version of eval_procedure
Remove unused stuff
Remove set_bindings
Remove some use of variable_unifier
Remove some use of unifiers from the embodiment combo interpreter
Remove test for function I just removed
Fixed bugs for executing a rule effect to a state .
remove calls to the old duplicate eval system that supported unifiers
Added a missing logic for processing if cannot find a proper rule for a subgoal during planning.
Fixed bugs in planner: Delete missing deleted pointers.
Fixed comparing if two states describe the same context.
Fixed logic for grounding a state, allowing the state value is left ungrounded.
Fixed grounding effect state process, allowing using the known old state value.
Merge github.com:jadeoneill/opencog
Fixed "is_pickupable" representation.
Record the arguments to a procedure