When eunit is terminating, a stop message is sent to all listeners and
eunit then waits for *one* result message but previously both
eunit_tty and eunit_surefire sent a response on error.  Don't send a
result message from eunit_surefire; let eunit_tty take care of all
result reporting, both positive and negative to avoid race conditions
and inconsistencies.

Ensure that all eunit listeners (like eunit_surefire) get the chance
to finish their work before terminating.  Prior to this fix, the
eunit_surefire XML was sometimes not generated.

Currently, error messages in Eunit Surefire reports are shortened just
like when written to a terminal.  However, the space limitations that
constrain terminal output do not apply here, so it's more useful to
include more of the error message.  Getting the full error message can
be particularly helpful when an assertMatch fails because of a long
and deep error term.

The new depth of 100 should be enough for most cases, while protecting
against runaway errors.