and rotates, auto-constrain translates in active workplane, speed
up remap list search with a hash table, other stuff.
[git-p4: depot-paths = "//depot/solvespace/": change = 1786]
just the mesh, no derived entities (but I suppose that I could turn
all points into circles).
And fix some bugs where equations didn't get unique IDs, and make
it possible to lock on to the group's workplane automatically, if
you press W while free in 3d with no workplane selected.
[git-p4: depot-paths = "//depot/solvespace/": change = 1780]