added bessel beam pulse and shape, plus corrections to making transversal source be zero
3D sources created (only x direction) and 2D sources updated
Merge pull request #3 from sanromd/_sources_dev

 sources dev
added 1D material shapes for non-linear chi3 and moving gauss
added 2D material shapes for vibrating membrane, moving gauss and double fiber
added line to decalr width of delta smooth function