replace many many usages of 'string path' with 'Path path' in prep for a cleanup on path usages
removed some use of Substring and pushed pathing logic down into the Path object
added a number of tests around the Path object
moved path combination into the path object
tweaked the getDrive code to support 'get-childitem /'
tweaked to support a nested path query
added GetHashCode to the Path. Started adding some file path tests. Added a file path test helper
upated set-location and get-location to work on mac