Previously, we had a start and a done of the calculation printed by
higher-level code, but this got intermixed by progress reporting from an
external solver or the output of autoremove code…
The higherlevel code is now only responsible for instantiating a
progress object of its choosing (if it wants progress after all) and the
rest will be handled by the upgrade code. Either it is used to show the
progress of the external solver or the internal solver will give some
hints about its overall progress. The later isn't really a proper
progress as it will jump forward after each substep, but that is at
least a bit better than before without any progress indication.
Fixes also the 'strange' non-display of this progress line in -q=1, while
all others are shown, which is reflected by all testcase changes.