Custom file dialog with "stop at main"

[emoon]

Something that is supported in the ProDG (for PS3) debugger is that when you select to load a executable you can check a checkbox called "stop at main" This is very useful for several reasons:

1. You don't need to setup any project but just start debugging directly and start stepping from the start.
2. It allows you to set breakpoints in the files you want before running the program without having a project setup.
3. It's possible to "browse" all the files that are referenced in the debug data of the executable (which has been loaded) to set breakpoints and look at included files.

In order to do this it would be good if it's possible to add some custom widget to the standard File Open Dialogs on Mac, Windows and Linux.

This is supported on Windows at least (as ProDG does it but I haven't investigated how) so it would be good to investigate this.