Optimisations for beam.translate about ott

[ilent2]

edbbac6 -- Add A,B matrices as output to all translate functions

[ilent2]

6f6528d -- translate_z now runs much faster, also produces non-square matrices.

[ilent2]

We could extend the scatter function to take a position and rotation argument. This would provide a clean way to hide this optimisation from the user.

[ilent2]

d68cef5 -- done. Still need to optimise examples, they are running really slow.

[an-kashchuk]

The default run of beam_visualisation.m has an error.
This command:
slm_beam = beam.translateXyz([5; 0; 0]);
doesn't copy the basis var to slm_beam and it contains 'regular' basis which creates an error in the following farfield calculation.
This will fix it:
slm_beam.basis = 'outgoing';

[ilent2]

Good spot. Thanks, I've fixed it in commit 2cefab9