Addind missing Aperture classes documentation
Merge pull request #60 from bsipocz/aper_adding_docs

Aperture photometry Aperture classes docs update
Add segment_photometry
Update segment_photometry docs
Allow label subset for segment_photometry
Change index to labels and make flux nan for invalid labels
Implement error, gain, and mask options in segment_photometry
Implement background option in segment_photometry
Add mask interpolation
WIP: segment_props
Rename segmentation module
WIP: segment_props
WIP: segmentation props
Clean up segment_photometry api docs
Move centroid, area, etc. from segment_photometry to segment_props; more clean up
Add make_gaussian_sources
Add make_random_gaussians
Add Possion noise option
Doc improvements to new make_* functions
More work on segment_photometry