Refactored the clause system so that most of the logic is in the yaml.
Moved the clause logic up into a clause manager, which exists on
the scene.
Moved some of the clauses into the scenario.  This is as much to
test the system as for any good reason, but it's not unreasonable.
convert tabs to spaces.
Added the isBlocklyExecuting clause.
Fix typos
Change "==" to "==="
Merge pull request #47 from virtual-world-framework/branch/refactor-scenario

Refactored the clause system so that most of the logic is in the yaml.