Moved Multivariate Constraint from failing to passing
Multivariate Constraint.R updated
Updated README file with directories added and make targets added.
Replaced a reference to "currentState" with generic "os" state in
handleFreeVar() function, and eliminated several pointer chases.
Starting to cleanup the code in the backend.
Added a failing test for data in a data.frame object. Also
minor cleanup of passing tests and demos.