(wishlist) outline: "new" method should be highlighted

[zenogantner]

It would be nice if methods with the name "new" could be marked in a special way.
Because "new" is the constructor be convention, it would be also nice to not hardcode this, but rather give the users the possibility to configure Padre to define colours (or other ways of marking) for all methods/subs where the name matches a certain regular expression.