adjusting download script to include UNFPA, WFP, and UN Habitat; adjusted process script to factor for new data, address errors and holes in new agency data, and adds country level centroids to activities without locations; also ran new process to get new data
adding some comments to python files
readme adjustment, moved contributing info to separate file, added base map from undp account
Merge pull request #3 from undp/updates

adjusting download script to include UNFPA, WFP, and UN Habitat; adjuste...