Add parser support for a few more operators

**
==
===
!=
=~
!~

Working on call expressions for some of these operators like unary !

"5.!" is a weird piece of ruby to parse.
Add parser support for calling methods on Fixnum

Perhaps a little hacked together, but not too bad. I'd rather this were
more generic, but we can solve that problem once we have more support for
calling methods on things (and especially once we support the correct
method names!)