Fix binary operator helper functions for Column prototype.

Several of the binary operator helper functions for the Column
prototype, i.e. 'notEquals', 'greaterThan', 'lessThan', etc., were still
using the 'values' function of the Expr prototype that no longer exists.
This resulted in an 'undefined' error.
Add functions representing all binary operators of an expresson.

Implemented all of the binary operators for an expression for
completeness.
Implement all SQL expression helper functions.

Implemented all of the helper functions to create any kind of SQL
expression following the syntax diagram for SQLite.