Bug 12263: Fix startup issues blocking response to HUP

Bug 12263: Fix startup issues blocking response to HUP

If you do a kill -s HUP sipserver_pid the server process
should restart its children.
This was not happening although it was logging the commencement
of the process.

Removed traces of Exporter usage this was always incorrect
this program inherits from Net::Server 'use base' to make inheritance
clearer. Removed unnecessary begin block

made file executable so it can run

added a shebang line so OS knows to invoke perl to compile and run
the file.

I've removed the debug code dumping the config to STDOUT,
it should not have gone into the production version.
One of the first things this program does is close stdout etc and
reopens the sip sockets to them. Assuming you can print to them other
than as part of the sip dialogue is not always safe.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>