Add tests for LVM -cow clearing

Ensure that volume_clear for Thick LVM snapshot deletion
references the -cow device, and that it uses the LV instead
of the -cow device for ThinLVM.

These tests were written for a change to stable/grizzly --
but are applicable for general use here as well.

Related-Bug: #1245529
Change-Id: I380ad7832d558d9aa73a701cbf3acc35229e70ab
Sync log from oslo

5fef5a8105 allow keeping of existing loggers with fileConfig
fb8075a19d Add amqp=WARN,qpid=WARN to default_log_levels
4654a5d247 Don't override default value for eventlet.wsgi.server logging
41ddd7a975 _get_log_file_path explictly return, when logfile/logdire unset
e12e6b45f8 Make openstack.common.log Python 3 compatible
572cfecb4d Make Messages unicode before hitting logging
3243cdfbe9 python3: handle module moves in log

DocImpact

Change-Id: I2e565fd65a00f1c6dea830a09487de9f03cb5279
replace u\2013 char with dash

unicode char causes problems with maven build.

backport:none

closes-bug: #1246569

Change-Id: I3aa5c2debaed03acd2c2fb8d4e7c30738d35f4f3
Merge "replace u\2013 char with dash"
Merge "Add tests for LVM -cow clearing"
Merge "Sync log from oslo"
Merge commit '14660991cb849c240acf41b377a7389b751cb6c7' into HEAD