StackTrace: ability to get stacktrace from thrown exceptions

[miyagawa]

If you app 'rethrow' exceptions to display stacktrace with StackTrace middleware, the middleware can't tell where the exception originally comes from - it's a problem with perl's exception handling. There's been patches to support getting stacktrace from thrown exception objects, but i'm wondering if there's a universal way to achieve this. Maybe impossible with the stock perl without XS voodoo...