Adding in ds9 region creation and annotated props structure

This is my first pull request, so if I'm doing it wrong let me know.  :-)

I added three files to my local cpropstoo repo. The first two (create_ds9_peaks.pro and create_ds9_regions.pro) create ds9 regions based on the cprops output to be overlaid in ds9. Right now create_ds9_peaks works in both pixel and angular units, but create_ds9_regions.pro only outputs in pixels. They are pretty basic right now, but could easily be extended. 

I have also extensively annotated the output props structure. Still needs some work, but I thought I'd give you what I have. Anyone else is welcome to take a hack at it. This was mostly for my sanity. Let me know if you'd rather not include this in the repo and I can take it out (although I have to figure out how to do that).