condor_ce_info_status updates

This set of commits turns the Resource class into the ResourceAd class, which is a subclass of ClassAd. This allows the attributes in the grid resource to be merged into the resource ad (instead of being a subclassad).

I've also removed the --query option (which caused a query ad to get created and used for matching). Instead, the script itself does the filtering. This ends up being more reliable and flexible.

Finally, I've made some refactorings that will enable me to split out the logic into a library, making it more reusable.