Added dynamic process property support

Charles,

My changes are a bit messier than I hoped because I had made some minor stylistic changes (adding some spaces, indentation, etc.) that I didn't later remove from my commit. Let me know if you'd prefer that I remove these. Not trying to step on your toes at all.

And to make things worse I accidentally added a semi-colon (harmless but sooo un-ruby!) that I removed with a second commit. Sigh.

I also went ahead and added .DS_Store files to the .gitignore, since I'm on OS X and I didn't want to check a bunch of those files in.

Let me know if you have any questions at all. Thanks for letting me doing this - good learning experience for me (haven't worked on a gem before)!!

Thanks,
Nathan