version from Jim which includes xyfwhm as an option in finding nearest neighbors, it also adds occupation checks, distance checks, and flags for using noise pixel or just position
old version which uses addition in combining the weights wheras newer versions use muliplication in combining weights
intermediate version with multiplicative weights and some of the xyfwhm but also some bugs
code to test the new pmap_correct and nearest neighbor codes which now use x and yfwhm to find the nearest neighbors eigther in the pmap dataset or in the science dataset itself.
cleaned up code somewhat, renamed some variables, added ability to find nearest neighbors in x, y, xfwhm, and yfwhm
plotting capability for xyfwhm nearest neighbor fitting
version now includes binning for xyfwhm