Fix find_autodoc_modules.sh to support OSX

When running 'find cinder/' on OSX platforms, all returned paths
will have 2 slashes (//). Because the script only strips
the first slash as per the CINDER_DIR value, we end up
with module names such as "cinder..db.api" in the documentation.

This change trims the leading dot if found to avoid this situation.

Change-Id: I9423b253d9842295850f469757e928bf5856967a
Deal with tgt already exists errors

This patch intends to provide a clear marker for
ER in the case that create export fails due to the
target entry already existing.

Also this patch will enable us to go ahead and just use
the existing target rather than bomb out and fail everything.

Root cause of why we're getting a second create is still
unknown and needs addressed, but this might help in getting
more info as well as keeping things stable until we address
the root issue.

Change-Id: If96f4fab7d9709dbb0726b1dca6237d7bc66ecbe
Partial-Bug: #1398078
Remove driver compatibility in volume manager

The old driver locations were deprecated in Juno. This removes the code
for deprecating and tests.

Change-Id: I1e2a985c1b41f4837e316af0655ef7203273cd7a
Merge "Deal with tgt already exists errors"
Merge "Fix find_autodoc_modules.sh to support OSX"
Merge "Remove driver compatibility in volume manager"