Each operation syntax must be fully customizable

The syntax for the unary operation (negation) and all the binary operations in the parser must be 100% customizable. In the binary operations, the notation (prefix, postfix, infix) and order (master operand = left operand; slave operand = right operand) should be customizable. As a consequence, I have to develop a function analogous to Pyparsing's operatorPrecedence (and propose it for inclusion in Pyparsing; it may come in handy even outside Booleano) -- it should automatically exclude operators in a higher precedence to avoid issues like Bug #397807.