and I am assuming that many more operations will require lookups in
the IdList<>.
Add code to represent and draw a 2d coordinate system. The origin
is described by a point, and the orientation by a quaternion. So
now it does the same thing before, and draws the reference planes,
but with a lot more lines of code.
[git-p4: depot-paths = "//depot/solvespace/": change = 1658]
9c2a8a08dc