In Entity.__sortkey__(), if one of the sorting attributes is a one to many relationships, sort the resulting sublist for this attribute in order to guarantee a unique sorting order.
In Entity.__sortkey__(), if one of the sorting attributes is a one to
many relationships, sort the resulting sublist for this attribute in
order to guarantee a unique sorting order.

git-svn-id: 5b1347ddac5aba1438c637217dfe0bb137609099@475 8efdbd46-c5fb-49ab-9956-99f62928ec21

icatproject/python-icat