rocon_app_manager: fixes capability-related error in app to message
method
rocon_app_manger: removes unused cap class
rocon_app_manager: fixes error when stopping a not running app
rocon_app_manager: adds some cosmetics (clean up, docs)
rocon_app_manager: applies major revamp to CapsList class
* determine supported capabilities (interface + provider)
* makes more efficient use of the SpecIndex class
* adds stub for provider remappings