Remove link to example application "Chirp", I no longer maintain it.
MOTOR-48 Add "How to Ask for Help" section to Github readme.
MOTOR-37 Delete tox.ini.

It can't represent the matrix of multiple Tornado versions and other dependencies,
so I'm not willing to maintain it. I'll rely on Jenkins and, to a lesser extent, Travis.
Use motor_test DB in exhaust cursor tests.
Debug test_exhaust_getmore_network_error.