nl_tokens: get a revision from the history with abbreviation support
pl_tokens: function ( systemId , revisionId , target , cb ) { if ( revisionId === EDITS ) { _getOnDiskVersion ( systemId , revisionId , <mask> , cb ) ; } else { findRevision ( systemId , revisionId , function ( err , rev ) { if ( err ) { return cb ( err ) ; } if ( rev === EDITS ) { _getOnDiskVersion ( systemId , revisionId , target , cb ) ; } else { _getRevision ( systemId , rev , target , cb ) ; } } ) ; } }