Added ability to make cuts

In FSPlotter

Added LilCutter class for making 2D cuts. Added Bounds class for
making 1D cuts. Added Cut() and InverseCut() to Plotter1D and Plotter2D.
Removed ability to make projections without filling 2D histogram i.e.
the ProjectX and ProjectY methods. Changed FillAndProjectX and
FillAndProjectY methods to ProjectX/Y.

In FSExcecutable

Added CMDpair class to handle optional arguments. Executable class
can now handle optional arguments. Run will read optional arguments
from the command line and will return them. Optional arguments have
the form 'name=value'. Optional args are stored into a CMDpair
object. CMDpair contains the pairs of names and values and can
search for strings having the same name.

In Plotter.cpp

Plotter can now load options by passing the name of the options file
from the command line when invoking Plotter. Updated to use the opt
arg functionality of Executable and the cut processing of Plotter1D
and Plotter2D. Disabled the 'auto' command because it is not
implemented inside Plotter1D/2D. Added separate x-axis and y-axis
1D histograms. Added the 'axis=x/y' optional argument for commands
involving the 1D histograms. Added the following new commands
'cut1D', 'cut2D', and 'cutran. Updated 'shist' to allow the saving
of all of the available histograms.