Do not leak SQL queries in HTTP 409 (conflict)

Log the exception details for debugging purposes when a SQL conflict
exception occurs when using the handle_conflicts decorator. Make
sure the raw sql queries do not get passed back to the end user.

Change-Id: If1ea528f0f9e486258d73b239015f370de2353ca
Closes-Bug: #1321804
Remove backend_entities from backend_ldap.conf

There's no configuration option in keystone for backend_entities,
so remove it from the test config file.

Change-Id: Id3b9bb609e6d1740b7db3543ce1316bf141553a0
Merge "Do not leak SQL queries in HTTP 409 (conflict)"
Merge "Remove backend_entities from backend_ldap.conf"