I added additional exception logging in the execution.py since
errors in processing results were really difficult to debug.

There is a problem on Windows with class serialization when
it comes from dynamically loaded module. To fix it I moved all
output processors to the tools/testrunner/outproc/ and import
them in test/*/testcfg.py.

Bug: v8:6917
Change-Id: Ida604641d659b006e91faf1d56a37769ec47f5f3
Reviewed-on: https://chromium-review.googlesource.com/842784
Commit-Queue: Michał Majewski <majeski@google.com>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50361}