locale: Fix localedef exit code (Bug 22292)

locale: Fix localedef exit code (Bug 22292)

The error and warning handling in localedef, locale, and iconv
is a bit of a mess.

We use ugly constructs like this:
      WITH_CUR_LOCALE (error (1, errno, gettext ("\
cannot read character map directory `%s'"), directory));

to issue errors, and read error_message_count directly from the
error API to detect errors. The problem with that is that the
code also uses error to print warnings, and informative messages.
All of this leads to problems where just having warnings will
produce an exit status as-if errors had been seen.

To fix this situation I have adopted the following high-level
changes:
* All errors are counted distinctly.
* All warnings are counted distinctly.
* All informative messages are not counted.
* Increasing verbosity cannot generate *more* errors, and
  it previously did for errors conditional on verbose,
  this is now fixed.
* Increasing verbosity *can* generate *more* warnings.
* Making the output quiet cannot generate *fewer* errors,
  and it previously did for errors conditional on be_quiet,
  this is now fixed.
* Each of error, warning, and informative message has it's
  own function to call defined in record-status.h, and they
  are: record_error, record_warning, and record_verbose.
* The record_error function always records an error, but
  conditional on be_quiet may not print it.
* The record_warning function always records a warning,
  but conditional on be_quiet may not print it.
* The record_verbose function only prints the verbose
  message if verbose is true and be_quiet is false.

This has allowed the following fix:
* Previously any warnings were being treated as errors
  because they incremented error_message_count, but now
  we properly return an exit status of 1 if there are
  warnings but output was generated.

All of this allows localedef to correctly decide if errors,
or warnings were present, and produce the correct exit code.

The locale and iconv programs now also use record-status.h
and we have removed the WITH_CUR_LOCALE hack, and instead
have internal push_locale/pop_locale functions centralized
in the record routines.

Signed-off-by: Carlos O'Donell <carlos@redhat.com>