When viewing 3D sequences, the horizontal and vertical
index is displayed in the bottom left of the viewer.
However, this just gives consecutive values as 1,2,3...
It should use the actual angle values in degree
returned by the server request for Horizontal-Views eg
0,15,30,45... etc. The system should allow for
sequences with missing images or non-uniform
acquisitions, in which cases knowing the actual angle
in degrees would be very useful.