Bug 15006: Introduce client_timeout in SIPconfig.xml

Bug 15006: Introduce client_timeout in SIPconfig.xml

Most selfchecks have persistent connections and send a
periodic status request at intervals (approx every 5mins appears
the norm) The timeout was dropping connections by default every 30secs
which for the client appears as a very flakey network.

This patch adds a separate parameter client_timeout that can be
used if you do want to force a disconnect if the client sends
no requests for a period. The sample config sets it to 600, but you
can also define a 0 value meaning no timeout. If the parameter is not
defined, it will fallback to service timeout.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Restored this patch from Colin in order to separate it from the
get_timeout patch. Adjusted the commit message slightly.
The original value of 600 from Colin's earlier patch may give less
discussion than setting to 0 (no timeout) in a later proposal.

Signed-off-by: Srdjan <srdjan@catalyst.net.nz>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>