Make the Show method accept any stream, default is current behaviour (stderr).
Can be used, therefore, also for stdout or even stringsteam.
Print a suitable timescale depending on the time recorded, from ns to s.
The function to pop a dialog is not really part of PROF_COUNTER,
if wanted, it can be done by the called.
This removes WX as a dep for PROF_COUNTER and profile,
which now used std::chrono only.
Also remove the print-to-stderr-with-delta function, as it's
unused too, and the delta times can be collected directly now
as std::chrono::durations if needed.
SCOPED_TIMER is a QA-only simpler version of PROF_COUNTER.
Extend PROF_COUNTER to allow access to the std::chrono::duration
for more flexibility.
Wrap PROF_COUNTER in SCOPED_PROF_COUNTER for RAII duration
output (for the same effect as SCOPED_TIMER).