Merge pull request #14 from swryan/dev

remove force_execute, no longer required since invalidation removed
moved heliopt to top level
added plots
modified a few output properties for plotting
Converted more MATLAB plots to matplotlib. Fixed __init__.py for heli_opt.
Merge pull request #15 from crobinsonut/plots

Converted more MATLAB plots to matplotlib
Uncommented all plots except structural deformation.
Merge pull request #16 from crobinsonut/plots

Uncommented all plots except structural deformation.
puts all figures into subplots of a single figure. legends are still wonky
Adjusted font size of plots. Fixed some latex for legends.
Merge pull request #17 from crobinsonut/plots

Adjusted font size of plots. Fixed some latex for legends.