- move the osc rpc managing thread into the osc and rename it appropriately

- move the osc rpc managing thread into the osc and rename it appropriately
- osc_rpcd's set is internal to the osc instead of passed in
- evolve the temporary 'barrier' api into the proper 'plug/unplug'
- move the 'ocp' management helpers from llite into genops.c
- start and stop osc rpc thread based on the presence of osc imports
- give test_rbw/echo_client the ability to use plug/unplug
- mirror some of the b_filterio test_brw/echo_client changes
- add an osc_internal.h for the osc rpcd