cxmanage: Add internal support for parallel commands
cxmanage: Add internal support for parallel commands

The controller will spawn a separate thread for each target.
Max threads is limited to 1 for now until I can test it more
thoroughly.

SilverLiningSystems/cxmanage-test2,SilverLiningSystems/cxmanage-test2,SilverLiningSystems/cxmanage-test,Cynerva/cxmanage,SLS-Dev/cxmanage,Cynerva/cxmanage,SLS-Dev/cxmanage,SilverLiningSystems/cxmanage-test