Minor refactoring
Enabled code analysis on build for all projects

Microsoft Managed Recommended Rules set.
EnsureDumpDirectoryExists now takes Uri
Changed 'Folder' to 'Directory'

For consistency, incl. with .NET System.IO.Directory class.
Added a comment on DirectoryPathBuilder usage
Renamed grab items collections for consistency
Minor changes in 'no items found' handling
Another minor refactoring