Bug 9250 - [SIGNED-OFF] provide commands to manage the SIP server

Bug 9250 - [SIGNED-OFF] provide commands to manage the SIP server

This adds commands required to control the SIP server. These commands
are:
* koha-enable-sip - copies the SIP config to the sites directory
* koha-start-sip - starts the SIP server processes
* koha-stop-sip - stops the SIP server processes

It also calls these as appropriate from the koha-common init script.

To use:
1) sudo koha-enable-sip instancename
2) sudo vim /etc/koha/sites/instancename/SIPconfig.xml
   Do whatever is needed for your site's SIP configuration
3) sudo koha-start-sip instancename

To test:
1) Build packages with this patch
2) Ensure that sudo koha-start-sip instancename doesn't do anything
3) Run sudo koha-enable-sip instancename
4) Edit /etc/koha/sites/instancename/SIPconfig.xml if needed (probably
   not required for testing)
5) Run sudo koha-start-sip instancename
6) Note that the sip processes are now running
7) Run sudo koha-stop-sip instancename
8) Note that the sip processes have gone
9) Reboot your Koha server
10) Note that the sip processes are back

Sponsored-By: Waitaki District Council Libraries
Sponsored-By: South Taranaki District Council Libraries
Sponsored-By: Horowhenua District Council Libraries
Sponsored-By: Rangitikei District Council Libraries
Signed-off-by: Magnus Enger <magnus@enger.priv.no>
Works as advertised. koha-start-sip without a prior koha-enable-sip
does nothing. koha-enable-sip copies the SIP config file to the
instance directory. After koha-enable-sip, koha-start-sip and
koha-stop-sip works as expected. After a reboot, the SIP processes are
still running. I have not actually tested the SIP servers after they
have been started, but assume they work the same as always.
The man pages look good.

The new commands should also have been added to the man page for
koha-common. I'll do a followup for that.
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
(cherry picked from commit 3dc22e7fb27162b3a461477bc40f5c38a1739516)

Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>