Big refactor: rmeoving the VarWithValue traits; still not compiling
more breakage
big refactor: all tests pass; assignments still lightly awkward
Assignment: catching the last naked asInstanceOf
big refactor: Assignments are now nice to use, assignment(v) returns v.Value; just update in HashMapAssignment is still a bit awkward and requires a type parameter
Merge pull request #57 from alextp/refactor-types

Refactor Var Value types