Fixed #82. The evaluation of an identifier assigns the oid to the Value returned.  Most of the time this will be the same, but for objects like Ints where the OID is special this technique allows us to not loose the value in question.
Assignment now prints out the last expression evaluated on the left hand side. This will have to change when doing arrays.
Removed the inclusion of the base in the printing out of a promise. This should probably be moved to the appropriate lib file.