Rename clause.py to clause_form.py
Make sure required function Unify and ClauseForm are implemented
Merge branch 'master' of github.com:ahmadsoliman/AIProject2

Conflicts:
	unifier.py
Fix trivial bug in action equality
Fix non-trivial bug in action equality.

Arrays of nodes don't have to be sorted, and sorting doesn't work on them
anyway beause there's no order defined. Don't assume sortedness.
Don't use the in operator while looking for actions in an array of actions
Print plans in a nicer way
More wake3y topological sorting
Turn on threat resolution
Fix trivial variable name overshadow
Add better output