Iterator

Implementation of an iterator that goes thru a Component and all its sub-components in a tree (pre-order) traversal. A test case that demonstrates the usage is also included, along with wrapping to make these iterators accessible from scripting..
This is an internal comment -- isn't this a user-visible class? If so there is a lot of doxygen missing (sorry!). Not just the class description here but none of the typedefs and methods have documentation either.