/** \brief creates a metafile area
\param name of area (does not show up on disk - purely for notation)
\param spec area specification (e.g. "/a:1G dir /b:2000M"
\param base base directory (NULL for no base)
/** \brief creates a metafile area
\param name of area (does not show up on disk - purely for notation)
\param spec area specification (e.g. "/a:1G dir /b:2000M"
\param base base directory (NULL for no base)