#485 ctrl+t for type hierarchy menu

[Yoni Tsafir]

In the java perspective of eclipse, Ctrl+T when you stand on a class name opens a type hierarchy menu of all the subclasses of this class, and Ctrl+T when you stand on a method opens a type hierarchy menu for all the subclasses' implementations of this method.

This should work in PyDev as well.

F4 for type hierarchy works nicely, but it opens in a different windows view and not as a menu, and also it doesn't work on methods.