unicode.7: Update to reflect past developments

The unicode(7) page will look more modern with few small changes:

- drop old BUGS section, editors cope with UTF-8 ok these days,
  and perhaps the state-of-the-art is better described elsewhere
  anyway than in a man page
- drop old suggestion about avoiding combined characters
- refer to LANANA for Linux zone, add registry file reference
- drop a reference to an inactive/dead mailing list
- update some reference URLs

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man7/unicode.7

@@ -213,14 +213,6 @@ and
 tells, how many positions (0\(en2) the cursor is advanced by the
 output of a character.
 .PP
-Under Linux, in general only the BMP at implementation level 1 should
-be used at the moment.
-Up to two combining characters per base
-character for certain scripts (in particular Thai) are also supported
-by some UTF-8 terminal emulators and ISO 10646 fonts (level 2), but in
-general precomposed characters should be preferred where available
-(Unicode calls this
-.BR "Normalization Form C" ).
 .SS Private area
 In the
 .BR BMP ,
@@ -232,8 +224,10 @@ range 0xe000 to 0xefff which can be used individually by any end-user
 and the Linux zone in the range 0xf000 to 0xf8ff where extensions are
 coordinated among all Linux users.
 The registry of the characters
-assigned to the Linux zone is currently maintained by H. Peter Anvin
-<Peter.Anvin@linux.org>.
+assigned to the Linux zone is maintained by LANANA and the registry
+itself is
+.I Documentation/unicode.txt
+in the Linux kernel sources.
 .SS Literature
 .TP 0.2i
 *
@@ -244,7 +238,7 @@ for Standardization, Geneva, 2000.
 
 This is the official specification of
 .BR UCS .
-Available as a PDF file on CD-ROM from
+Available from
 .UR http://www.iso.ch/
 .UE .
 .TP
@@ -267,7 +261,7 @@ which improved wide and multibyte character support even further.
 *
 Unicode Technical Reports.
 .RS
-.UR http://www.unicode.org\:/unicode\:/reports/
+.UR http://www.unicode.org\:/reports/
 .UE
 .RE
 .TP
@@ -276,39 +270,18 @@ Markus Kuhn: UTF-8 and Unicode FAQ for UNIX/Linux.
 .RS
 .UR http://www.cl.cam.ac.uk\:/~mgk25\:/unicode.html
 .UE
-
-Provides subscription information for the
-.I linux-utf8
-mailing list, which is the best place to look for advice on using
-Unicode under Linux.
 .RE
 .TP
 *
 Bruno Haible: Unicode HOWTO.
 .RS
-.UR ftp://ftp.ilog.fr\:/pub\:/Users\:/haible\:/utf8\:/Unicode-HOWTO.html
+.UR http://www.tldp.org\:/HOWTO\:/Unicode-HOWTO.html
 .UE
 .RE
-.SH BUGS
-When this man page was last revised, the GNU C Library support for
-.B UTF-8
-locales was mature and XFree86 support was in an advanced state, but
-work on making applications (most notably editors) suitable for use in
-.B UTF-8
-locales was still fully in progress.
-Current general
-.B UCS
-support under Linux usually provides for CJK double-width characters
-and sometimes even simple overstriking combining characters, but
-usually does not include support for scripts with right-to-left
-writing direction or ligature substitution requirements such as
-Hebrew, Arabic, or the Indic scripts.
-These scripts are currently
-supported only in certain GUI applications (HTML viewers, word processors)
-with sophisticated text rendering engines.
 .\" .SH AUTHOR
 .\" Markus Kuhn <mgk25@cl.cam.ac.uk>
 .SH SEE ALSO
+.BR locale (1),
 .BR setlocale (3),
 .BR charsets (7),
 .BR utf-8 (7)