set_altitude, set_azimuth were disabled by new spec code about owl

[ryanrhymes]

  p.altitude <- _get_altitude spec p.altitude;
  p.azimuth <- _get_azimuth spec p.azimuth;

Yes, this is better than my current code so I have changed it, many thanks.

So maybe set_altitude and set_azimuth should be removed, and the default values left in hardcoded surf and mesh?

I agree that it is not very common to call 3d plot multiple times in one figure, so I have removed the set_altitude and set_azimuth for the time being. But it can be added back in future whenever the usecase becomes clear.