Fix (really) tests simpleOneDB and digestLength1.

The previous fix correctly set the active configuration but
only set it *after* the servers started. By that time, changes
to config had no effect.

This fix defines special configurations for tests before any
test is activated. As a result, the special configuration is
used at startup of the servers, when it will actually take effect.

Test runs of this fix have been more extensively instrumented than
prior "fixes", so I have more confidence that this fix fixes the fix.

For digestLength1: The active configuration was printed from every
DB instance. The config['digest-length'] was correctly set.

For simpleOneDB: The active configuration was printed from every
DB instance. The config['digest-length'] and config['ndb'] were
correctly set.  After the test, the Redis servers were checked
and only the Redis server for DB0 had any keys.
Merge branch 'master' of http://innovate.cs.surrey.sfu.ca/code/533f90cda342aec8c7386aea