Var.rev

[Antony Lee]

While trying to get rid of the duplicate constructors (Symbol/symbol, Var/var, Keyword/keyword), I discovered the ".rev" field of Vars and can't see what it's used for -- I can delete it and everything still works fine.  Anyone knows what it's for?
Anyways, the new versions of the constructors (with docstrings! :-)) is in the "cleanup" branch of my repo.
Antony