one point to be dragged simultaneously. So now a dragged point
drags all the selected points and entities, and a dragged entity
drags its points (except for circles, which drag the radius).
This means that the number of forced points for the solver must now
be unlimited, and it is.
Also add commands to invert the selection within the active group,
and to select an edge chain starting from the current selection.
And redo the context menus a bit; still not great, but less
cluttered and more systematic.
[git-p4: depot-paths = "//depot/solvespace/": change = 2064]
we're inconsistent (singular Jacobian). That's slow, so we should
provide a library interface to disable it.
[git-p4: depot-paths = "//depot/solvespace/": change = 1946]
little test app that links against it. I still need to polish a few
things, but this is more or less as it should be.
[git-p4: depot-paths = "//depot/solvespace/": change = 1944]