Mapping Standards Directory Update

I've added a few new sites to the mapping standards directory. The new additions include a mapping manual from Minnesota DOT, a presentation on accuracy standards for mapping projects in North Carolina (from the NC ASPRS chapter), and various mapping specs from the Nova Scotia Geomatics Centre. All three are in the "Provincial/State Level Standards" section.

In particular the Surveying and Mapping Manual from Minnesota DOT provides a wealth of information, and it is relatively recent (updated in 2007).