Make it work under WIN32 (ugh); and allow CAVETime.
Allow null time ranges so partiview can suppress time bar
if nobody has nonempty range.

Add new "trange" command to specify a limited range of times we're
allowed to view.

Handle wrap band correctly (no extra ";"!).

Lots of changes to support new time flow and additional
time-related GUI.  Probably not all there but at least somewhat usable.