Allow tox tests with complex OS_TEST_DBAPI_CONNECTION URLs

In particular, this allows OS_TEST_DBAPI_ADMIN_CONNECTION URLs with
alternate drivers like mysql+mysqlconnector://... to survive through
into OS_TEST_DBAPI_CONNECTION for the actual unittest.

Change-Id: I712d9366e616a551f4b2bd225de42469a35b363f
Remove sqla_07 from tox.ini

Remove support of sqla_07 test according to global requirements

Change-Id: I1c4817c28b779bdb6467e346a38147b193f58a38
Imported Translations from Transifex

Change-Id: I4f7fa49a954d773b2f8784511cc9017ed9226e7c
Extension of DBDuplicateEntry exception

Added new field 'value' for DBDuplicateEntry exception.
It shows duplicated value for mysql and postresql 9.x engines
and is read from the error message using regular expressions.

The duplicated value can't be extracted from SQLite error messages,
so we do our best here for other db backends that we support.

Change-Id: I647e314cafe8ceb570bf18948d6ab83ab6afef97
Merge "Allow tox tests with complex OS_TEST_DBAPI_CONNECTION URLs"
Merge "Remove sqla_07 from tox.ini"
Merge "Imported Translations from Transifex"
Merge "Extension of DBDuplicateEntry exception"