Generalize orisel to handle more pulse shapes

[stestoll]

In 5.2, orisel assumes an excitation profile that is Gaussian with frequency centered at Exp.mwFreq and FWHM given by Exp.ExciteWidth. The function should be able to take more general pulse shapes as well.

That would of course mean that the analytical convolution with the convolutional Gaussian broadening in Sys.lw or Sys.lwpp needs to be generalized and probably done numerically.

Also, orisel should return the coordinates of the orientational grid, theta and phi.