setlocale.3: Remove now obsolete NOTES section

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
locale.5: Clarify lang_term / lang_lib

As noted by Keld Simonsen in the lib-locales@sourceware mailing
list:

    https://sourceware.org/ml/libc-locales/2014-q2/msg00008.html
    From: Keld Simonsen <keld at rap dot rap dot dk>
    To: Marko Myllynen <myllynen at redhat dot com>
    Date: Tue, 29 Apr 2014 17:02:09 +0200

    lang_term reflects ISO 639-2/T (terminology) codes, while
    lang_lib reflects ISO 639-2/B (bibliographic) codes.
    lang_term is preferred over lang_lib codes for locale names.
    There are 20 specific ISO 639-2/B codes.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
setlocale.3: wfix

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
setlocale.3: Simply locale category listing and add GNU-specific locale categories

Some information that was here will move to locale(7).

Reported-by: Marko Myllynen <myllynen@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
locale.7: Add further details on various categories

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
locale.5: Clarify LC_TIME/am_pm and LC_NAME keywords usage

am_pm should be defined only if AM/PM convention is used to signal
applications they should not try to print them when using them in
unwanted.

Same for all LC_NAME keywords expect for name_fmt which should be
always defined.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
locale.5: Tweaks to Marko Myllynen's patch

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
locale.5: Minor rewordings

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
nl_langinfo.3: expand the example code a bit

Better illustrate querying elements from different categories.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
locale.7: Document LOCPATH

Example from https://sourceware.org/glibc/wiki/Locales

After modifying a locale, make sure it compiles, and install it to a
temporary directory for testing:

  unset LC_ALL
  LOCALE=fi_FI
  export I18NPATH=$HOME/locale-test/
  export LOCPATH=$HOME/locale-test/
  mkdir -p $LOCPATH
  localedef --no-archive -f localedata/charmaps/UTF-8 -i localedata/locales/$LOCALE $I18NPATH/$LOCALE.UTF-8
  LC_TIME=$LOCALE.UTF-8 locale -ck LC_TIME
  LC_TIME=$LOCALE.UTF-8 locale -ck date_fmt
  LC_TIME=$LOCALE.UTF-8 date
  LC_CTYPE=$LOCALE.UTF-8 iconv -f UTF-8 -t ASCII//TRANSLIT < translit-test-input.txt
  LC_COLLATE=$LOCALE.UTF-8 sort < sorting-test-input.txt

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
locale.7: Tweaks to Marko Myllynen's patch

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