Add 'not(' Operator

[JEbertPrime]

The not( operator (wiki post) is equivalent to JavaScript's ! operator, but differs in a few key ways.

• Everything after the operator is evaluated before not, including logical operators and mathematical expressions.

Disp not(1 and 0
//1
Disp not(1 and 0 or 1
//0

• A close parenthesis is not required, but can be used to enclose a not( operator within a line

Disp not(1) or 1
//1
Disp not(0) or 0
//1

The operator takes a single argument of the same types as other logical operators, and can be nested.
I foresee this being a fairly simple rule to implement in the parser, considering the already implemented support for other expressions using (.