Don't translate debug level logs in nova.spice, storage, tests and vnc

Our translation policy
(https://wiki.openstack.org/wiki/LoggingStandards#Log_Translation) calls
for not translating debug level logs. This is to help prioritize log
translation. Furthermore translation has a performance overhead, even if
the log isn't used (since nova doesn't support lazy translation yet).

Change-Id: I5964d2f6a4328b91d67c0d8fd514e1eb7c6048bb
Dedup devref on unit tests

We already have a document on how to run unit tests, so
development.environment should just point to that document instead of
trying to summarize it.  Keeping this information in one less places
makes it easier to make sure the page is up to date (which
development.environment is not -- no mention of tox).

Change-Id: I9aecf439b6145b035b3457559ddb187058f5057b
Merge "Dedup devref on unit tests"
Merge "Don't translate debug level logs in nova.spice, storage, tests and vnc"