sympy.physics.gaussopt module patch

[alexandr popov]

Hi,

Just finished to perform PATCH requirment for GSoC.

https://github.com/sympy/sympy/pull/1219

Added the beam_plot and beam_plot2 utilities (one of TODO tasks) for plotting gaussian beam propagation (waist parameter). The first one uses pyglet (this method appears to be not convenient and unstable for such purpose), the second uses matplotlib (looks good and works stable).

Also added BeamExpansionFactor class [1] and SingleRightAnglePrism class, which uses the first. Features concerning prisms can be implemented via these basic classes.

1. (http://www.springerlink.com/content/b048n408137185p2/)

[krastano...@gmail.com]

Thanks for the additions. I will comment directly on the pull request page.

[alexandr popov]

The patch was revised. 

The discussion on "gaussopt module patch" is opened in new pull request https://github.com/sympy/sympy/pull/1226