Bug 5586: Set SIP line-endings to proper SPEC-compliant \r

Bug 5586: Set SIP line-endings to proper SPEC-compliant \r

Line-endings have been a longstanding problem because
of variations in implementations.  But we should still try
to default to the correct thing.

This harmonizes part of Koha's SIP code with the current
SIPServer version, used in common with Evergreen.  Repo at:
    https://github.com/atz/SIPServer

Signed-off-by: Ian Walls <ian.walls@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>