glance-replicator: enable logging exceptions into log file

bug 1213779

Currently, glance-replicator provides option to enable logging
information into a specified file. But exceptions are not logged
into the log file when they are thrown.

Reproduce steps:

When setting a wrong source or target address, exceptions would be
thrown, but not logged into log file.

Change-Id: Ic2c59e04aa6099f3ede0c6b8579c31a3dfff895c
image-delete fires multiple queries to delete its child entries

1. Changed individual query calls for soft-deleting the image's
   child entries to one db query call for all child entries of a
   given type.
2. Added a fix to simple db's 'image_destroy' api to clear
   the location entries.

Fixes bug 1201758

Change-Id: Ib673de5460d59ea3af74553048ffcf74dccbdc36
Merge "image-delete fires multiple queries to delete its child entries"
Merge "glance-replicator: enable logging exceptions into log file"