Eval: inline condition operator condition?if_true:else

- fixes #39
Parse/Compile Eval: differenciate between ary/unary operators
Eval: function neg(), unary negation: -fun()
Eval: equal: also accept '=' as operator
Eval: identifiers may contain #
Eval: functions red(), green(), blue(), alpha()
Eval: rename lefthandtraffic() to is_left_hand_traffic() (and right* too)
Eval: new functions regexp_test() and regexp_match()