Create a loglevel property attribute.  The set_loglevel is still there, but should be set to be deprecated.
Fixed bug in IO.PNM.save/load that appears now that the propname argument is automatically sent to models
Added a method to misc that clones an object, including connecting other objects to self, but DOES NOT connect self to other objects.  This clone is meant to be a ghost that disappears when no longer needed.
A few touch-ups on set_boundary_conditions...it wasn't allowing assignment to single pores.