Added backward projection function
Added 2 extra variables to filepath
Added more comments to configuration file that will be printed out
each time WriteParameterFile is called
This will effect both forward and backward projection functions in
siddon_recon class
test
Added comment on mlem.cu file
forward_projection function is still not checking all

folder and files inside the configuration file,
which creates an error
Added more error for file, folder, and size

Working as intended, tested both forward and recon functions
Added the master parameter file for safe keeping
Merge branch 'home_8_19_2014'