Man pages for libtoolize and libtool, --help-all.

Man pages for libtoolize and libtool, --help-all.

* Makefile.am (dist_man1_MANS, update_mans): New macros.
($(srcdir)/doc/libtool.1, $(srcdir)/doc/libtoolize.1): New
rules.  Use --help-all for libtool.
(MAINTAINERCLEANFILES): New macro.  Add dist_man1_MANS.
(BUILT_SOURCES): Add libtoolize.
* configure.ac: Check for help2man, set HELP2MAN.
* doc/libtool.texi: Add @direntry for libtool-invocation.
(Invoking libtool): Document -h, --help-all.  Reorder mode
description for consistency.
(Compile mode): Do not document -Wl,FLAG and -XCClinker here.
(Link mode): Document -Wc,FLAG here, reformat a bit.
* libtoolize.m4sh: Reformat --help output a bit, to help
help2man.
* libltdl/config/ltmain.m4sh: Likewise.  Also, set PROGRAM to
`libtool', not `ltmain.sh', so the former is used in the man
page.
New argument `--help-all'.  If given, call func_help and
func_mode_help several times, beating output in shape with sed.
(func_mode_help): Do not exit here.
* libltdl/config/getopt.m4sh (func_usage): Work with different
indentations, but require comment hash in first column, when
grepping for '-h' in usage to end short help.
(func_help): Accept optional argument to not exit.
* NEWS, THANKS: Update.
Suggestion by Karl Berry.

Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>