The router dispatches packets to another StreamResult based on their
route_code, stripping the matching section. Unroutable events are forwarded to
a fallback stream.

This allows event generators to ignore the timestamp field, it can be added
into the stream - as long as it is before any buffering/queueing/blocking occur
it will be accurate enough.

This permits running existing tools like test runners and reporters with
StreamResult generating test runs adapting any unittest or testtools compatible
TestResult into a StreamResult.

This permits using code that uses any Python unittest test code
with a StreamResult.

This is equivalent the to behaviour in the TestResult class, but split into a
dedicated helper (so that decorators and the like don't need to waste cycles
generating them).

This avoids all of the buffer management and analysis and should be suitable
for most terminal filters.

This allows applying multiple terminal handlers to one stream.