bug in quiver3

[Kai Habel]

Hello all,

while working on a surfl.m implementation, I noticed the following
problem in quiver3 using the recent tip.

I cannot plot single vectors with quiver3 like:

quiver3(0,0,0,1,1,1,'Color','red')

This should give a vector originating at (0,0,0) and ending at (1,1,1)
but I get a plot with axes only.

I see another problem with:

quiver3([0 4],[0 4],[0 4],[1 1],[1 1],[1 1],'Color','red')

Here I would have expected a plot with two vectors  (1,1,1) originating
at (0,0,0) and (4,4,4) but I get a plot with two vectors originating at
(0,0,0) and ending at (1,1,1) , (4,4,4) respectively.

I have confirmed with matlab, the examples above are valid inputs for
quiver3.

Kai