Generate apache-style common access logs

Taking advantage of this middleware either requires enabling
verbose/debug or utilizing an external logging.conf which configures an
'access' logger.

Example output:

  127.0.0.1 - - [2013-01-29T17:15:02.752214] "GET http://localhost:5000/v3/projects HTTP/1.0" 200 16

This patch also revises etc/logging.conf.sample with some more practical
defaults (e.g. supporting externally-managed log rotations) in addition
to illustrating how to generate an 'access.log' file.

DocImpact

Change-Id: I2a6048fa5fbf8661a6859d9e3a259d4cfa5fc589
Merge "Generate apache-style common access logs"