This patch enable clients of core's TRACE service to obtain the
execution times of trace subjects (i.e., threads). The execution time is
delivered as part of the 'Subject_info' structure.
Right now, the feature is available solely on NOVA. On all other base
platforms, the returned execution times are 0.
Issue #813
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082