Custom default exception handler?

[Nick Sabalausky]

I don't suppose there's a way to change the default exception handler 
without using a modified druntime? I'm not seeing one in the docs, but I 
could have overlooked something.

Replacing a druntime function at link-time wouldn't be ideal because 
then druntime's handler couldn't be called as a fallback, at least 
without maintaining a duplicate of druntime's handler and keeping it in 
sync with the version of druntime being used.