Individual practice sims, single ownership outputs, acreage outputs, and other fixes

[msimmond]

This update resolves issues #44, #35, #37, and #40, which involves (1) adding the ability to generate batches of individual input files for isolating the effects of individual practices, (2) creating diagnostic plots and csv files of single ownership level outputs, (3) reading in or outputting area units in acres or hectares, (4) adding interpolation routine for missing years of climate scalars, and other bug fixes.

[aldivi]

merging into master so that we can each make new branches to finish up the final changes before running