(info-insert-file-contents-1): Accept an additional

(info-insert-file-contents-1): Accept an additional
argument `lfn': if it is non-nil, concatenate `filename' and
`suffix'; otherwise use the complicated MS-DOS code.  All callers
changed.
(info-insert-file-contents, Info-find-node): If the MS-DOS port
can access long file names, try the long file-name version of
`info-insert-file-contents-1', then the short file-name version.