This commit returns the build to a working state.  The Summary is now
generated from @standards, and syntax-checking is performed.  If
invalid @standards syntax is detected, summary.pl will fail, reporting
all errors.  Failure and error reporting is disabled for now, however,
since much of the manual is still incomplete wrt. header and standards
annotations.

Note that the sorting order of the Summary has changed; summary.pl
respects the locale, like summary.awk did, but the use of LC_ALL=C is
introduced in the Makefile.  Other notable deviations are improved
detection of the annotated elements' names, which are used for
sorting, and improved detection of the @node used to reference into
the manual.  The most noticeable difference in the rendered Summary is
that entries may now contain multiple lines, one for each header and
standard combination.

The summary.pl script also accepts a `--help' option, which details
the expected syntax of @standards.  If errors are reported, the user
is directed to this feature for further information.

	* manual/Makefile: Generate summary.texi with summary.pl.
	Force use of the C locale.
	* manual/header.texi: Update reference to summary.awk.
	* manual/summary.awk: Remove file.
	* manual/summary.pl: New file.  Generate summary.texi, or fail
	in the face of syntax errors, reporting them.
---
 manual/Makefile    |   7 +-
 manual/header.texi |   2 +-
 manual/summary.awk | 133 -----------------
 manual/summary.pl  | 423 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 427 insertions(+), 138 deletions(-)
 delete mode 100644 manual/summary.awk
 create mode 100755 manual/summary.pl