Bug 9531: Make SIP2 message terminator configurable via SIPconfig.xml

Bug 9531: Make SIP2 message terminator configurable via SIPconfig.xml

Add a terminator option to SIPConfig.xml, choices for 'terminator' are
'CR' or 'CRLF'.  The default continues to be 'CRLF' if 'terminator' is
undefined.

Test Plan:
1) Apply patch
2) Start SIP server
3) Run C4/SIP/t/04patron_status.t
4) Stop SIP server
5) Add terminator="CR" for account login 'term1'
6) Run 04patron_status.t again, you should see no change

Signed-off-by: Frédéric Demians <f.demians@tamil.fr>
Signed-off-by: Adrien Saurat <adrien.saurat@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>