Refactor extrude_wire from twist_extrude_wire.
Separate twisting (twist_extrude()) from extrusion (extrude_shape(),
_face()).
Implement revolution_render with @angle=nil using extrude_shape
and a gp_Circ.

This means that tolerance is set correctly.
Default revolve angle parameter to nil, not 360 degrees.

(Almost the same thing, though.)
Implement revolution_render with angle using extrude_shape().

This means tolerance is set correctly.
Clamp revolution angles between 0 and 2pi.
Remove unnecessary comment.
Measure revolution angles from +X to +Z not from +Z to +X.