separation of initialization of children from launching of the children;
children launching is started in a greenlet in on_start; initialization then
verifies the children have been launched to proceed.
merge upstream/master
workarounds for the recent issues related with the new hasNetworkParent
association, which is not yet handled by the enhanced registry. I just
explicitly  implemented unresolved functions
merge workarounds_for_dynamic_functions
Implement launch of the children agents (sub-platforms and instruments) on_start  (and terminate them on_quit) as opposed to lauching them in INITIALIZE (and terminathem in RESET). All tests OK but method not enabled because the termination of the processes is not completely clean: there are exceptions with "already dead?" messages, and also the logic is a bit more complicated: need to launch the children asynchronously  as the direct launch in on_start does not work (timeout).
merge upstream/master
remove temporary workaround for bug related with hasNetworkDevice and lack of
 support in enhanced resource registry, now fixed.
minor adjustment and a check to avoid unnecessary exception if platform
network was not created or launched properly
merge upstream/master
make sure self.p_root is defined
use correct RR2 calls eg.,
assign_instrument_agent_instance_to_instrument_device_with_has_agent_instance
 instead of assign_instrument_agent_instance_to_instrument_device)
Merge pull request #821 from carueda/platform_instrument_coordination

launch children agents as part of the launch of the parent platform and adjustments per fixes in enhanced resource registry arising from new hasNetworkDevice