Bug 15956: New unit test SIP/Message.t

Bug 15956: New unit test SIP/Message.t

This patch adds a unit test for the handlers of Patron Status
and Patron Info requests. It can be extended with test for the
other handlers later (hopefully).

Note: The tests have been written for SIP protocol version 2.

Test plan:
Run t/db_dependent/SIP/Message.t.

Note: If bug 13871 has not yet been pushed, test 12 (subtest 1) should fail
with something like 'Code AF not found'. Same for test 15 of subtest 2.
That is no problem; after that push, all tests should pass.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
All tests pass
t/db_dependent/SIP/ILS.t .......... ok
t/db_dependent/SIP/Message.t ...... ok
t/db_dependent/SIP/Patron.t ....... ok
t/db_dependent/SIP/Transaction.t .. ok
All tests successful.

No errors

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>