Use directory traversal to shorten path in prompt
Uses full name for Git or Hg repo folders
Combine Git and Hg functions into Is-VCSRoot
Fix prompt for UNC paths
Fix path to user home directory in prompt
Fixed some UNC drive issues
Using wildcard in drive color switch
Added in test framework and some tests
Merge pull request #10 from chrisbenti/Pull9

@derekerdmann's changes plus UNC fixes and tests