Changed the package name for arbil trunk from mpi.linorg to nl.mpi.arbil.\nAdded error message for mac users when a file cannot be opened in an external application.
Changed the package name for arbil trunk from mpi.linorg to nl.mpi.arbil.\nAdded error message for mac users when a file cannot be opened in an external application.

TheLanguageArchive/Arbil,TheLanguageArchive/Arbil,TheLanguageArchive/Arbil,TheLanguageArchive/Arbil,TheLanguageArchive/Arbil