trying to add forward projection to recon class

not finished yet
continue to add forward projection function
Added more error checking for forward projection.
Still need a display for the prompt
Modified WriteParameterFile class to specify either forward or reconstruction
parameter file ('.cfg');
modified siddon_recon class functions
took away public a1_recon_initiate() and put into protected section
as m1_recon_initiate()
Added some comments and moved renamed some public variables so they show up better in visual studio
Merge branch '8-18-2014'