Clean up logging levels

The following logging levels are set according to the combination of
--verbose, --quiet and --debug options:

verbose_level   logging level       options
0               --quiet             ERROR
1               (none)              WARNING
2               --verbose           INFO
3+              --verbose --verbose DEBUG
                or --debug

Logging levels for the requests and iso8601 modules are forced to ERROR.

This is the first step in bp use-logging-not-print

Change-Id: Ide2233b3316471d279260fb1e7255a6ca2072023
Add basic timing support

Add support for novaclient's --timings option.  Due to the transition
to cliff for all data output a psuedo-command Timings is created
to handle output formatting.

TODO:
* make get_timings() modular for all plugged-in clients
* extract format and colums options from previous command so
  we can not hard-code '-f table'

Change-Id: I7f1076b7a250fba6a8b24b2ae9353a7f51b792b2
Merge branch 'server-image-create-fix' into dt-test
Merge branch 'image-set-fix' into dt-test
Merge branch 'timings' into dt-test
Merge branch 'fix-logging' into dt-test
Merge branch 'new-session' into dt-test
Merge branch 'identity-ec2-tests' into dt-test