Logging audit for trove/mysql module

Adjust logging to conform to logging standards.
Cleaned up a few messages that are unclear and
changed some LOG.info messages to LOG.debug.

Also fixed a pattern of having an exception with
the sole purpose of logging an error with the
value thrown and replaced with LOG.exception
instead.

Added LOG.debug messages to the mount, unmount
and resize methods in service.py; this change
was made to all datastores.

Change-Id: If2a5c95b806e555d077ce494f474d3463fda6794
Partial-Bug: #1324206
guestagent/test_volume.py leaves a file in /tmp

Since the test mocks() execute and then calls write_to_fstab(), the
file created in /tmp by write_to_fstab() stays around. This is because
write_to_fstab() uses execute to remove the file. Replaced it with an
os.remove() and fixed the test which was counting two calls to
execute().

I'm fixing it because testing for another bug involves running tox
over and over again and leaving these files in /tmp is just a bit
messy.

Change-Id: Ia9e01049687644abd0671a658dffbbdcb4fba4bd
Closes-Bug: #1353064
Merge "Logging audit for trove/mysql module"
Imported Translations from Transifex

Change-Id: I40c3f824bf27a5433e7ca55c7423dc19e49f00c9
Merge "guestagent/test_volume.py leaves a file in /tmp"