Fixed the directory scanning monitor so that it skips over IO & access exceptions when traversing the directory tree.
Moving exception to Core.
Adding import
Merge branch 'master' of github.com:abb-iss/SrcML.NET
Fixed namespace for directoryscanning monitor subdirectory exception.
Fixed problem where forbidden directories were added to the source monitor https://trello.com/c/AddIlC1J
Merge branch 'master' into topic-data-incrementalupdate