Feature request: TortoiseMerge should have an option to defer to an external tool if it detects a binary file

[Ryan Niehaus]

It would be great if TortoiseMerge would be able to defer to an external merge tool when it detects binary files so that we don't have to have specific extensions mapped ahead of time in the TortoiseSVN settings.  I have several small binary formats, some without any extensions, that would be great to be able to diff without jumping through hoops to do it.