See merge request !18

Fixup: the change from numeric to uint32 seems not supported for the release of open62541 which is by default used by the OSIE coupler.

The custom opcua server bind option is added and it can be
parced with command line option -a or server_ip_address=.
If no ip address is mentioned, then server is listening on all interfaces

modified:   cli.h
modified:   keep_alive_publisher.h
modified:   keep_alive_subscriber.h
modified:   server.c

Test: Program is tested

See merge request !17

See merge request !16

Add a new CLI option to set the timeout after which without a heart beat a dependant coupler is considered DOWN.

Make network address url data type configurable so we can support both IPv4 / IPv6 multicast from  CLI.