Rotate.m function fixed

Surf property "vertexnormals" are updated correctly.

Bug evidence:

[x,y,z] = sphere(20);
hs=surf(x,y,z,'facecolor','y');
view(2)
axis equal
hl=light;
lightangle(hl,0,0)
% light is on -Y axis, thus at the
% bottom
rotate(hs,[0 0 1],30)
% rotate sphere to the right from 30°

It looks like the light has moved. This is due to a bug in rotate.m function. The "VertexNormals" property of the surf object is not updated as "xdata", "ydata" and "zdata" properties are.

This is fixed in the submitted version of rotate.m.

Luc Masset