medium: ui_resource: Make op an optional argument to trace/untrace
medium: ui_resource: allow trace of resource without specific operation

Simplify use of trace/untrace even further by allowing the form
'trace <rsc>', which will trace all configured operations plus the
start and stop operations regardless.
medium: ui_resource: Also trace promote/demote for multistate resources
Merge pull request #31 from krig/retrace

medium: ui_resource: Make op an optional argument to trace/untrace