Nested exception support

[kmate]

An excerpt from the Bugsnag API docs:

        // An array of exceptions that occurred during this event. Most of the
        // time there will only be one exception, but some languages support
        // "nested" or "caused by" exceptions. In this case, exceptions should
        // be unwrapped and added to the array one at a time. The first
        // exception raised should be first in this array.
        exceptions: [{
...

[raszi]

Is there any chance that this will be merged?