Started to split Diffraction into Calculated and Experimental  subclasses
Completed split into Experimental and Calculated patterns
Bug fix: Diffraction file always being "set"
Bug fix: Forgot to multiply by 2 when storing angle of calculated peak
Bug fix: Forgot to match peaks before refining a structure
Overhauled -diffraction command.
Added in ability to generate raw diffraction patterns
Added in Reitveld refinement for everything but atomic positions
Added in Reitveld refinement
Merge origin/master