Bug corrected in hidden steps now allows all IO tests to run.

Was not properly accounting for the length of the specified property keys array (was only accounting for null) and so the hidden keys were not being found and assigned so none were getting written to GraphSON.
Trying to get GraphStrategy back on its feet after metaproperties refactoring.

There are many things wrong now given this new model.  There exist many cases where Property and MetaProperty are not wrapped in a strategy wrapper class.  Still need to find all those spots and fix them.