Equals and not equals should be able to match Boolean types

[Sean Kauffman]

In a where expression, equals and not equals log errors when they are used on Booleans. This is wrong, as it should be possible to say that two Boolean expressions are equal.

C :- A before B where A.foo = B.bar

A|10|foo|true
B|20|foo|bar

[Sean Kauffman]

This is easy to fix

[Sean Kauffman]

commit 543cb3d

[Sean Kauffman]

Added support to expression evaluation