localedef: Add --no-warnings/--warnings option

localedef: Add --no-warnings/--warnings option

From localedef --help:

Output control:
...
      --no-warnings=<warnings>   Comma-separated list of warnings to disable;
                             supported warnings are: ascii, intcurrsym
...
      --warnings=<warnings>  Comma-separated list of warnings to enable;
                             supported warnings are: ascii, intcurrsym

Locales using SHIFT_JIS and SHIFT_JISX0213 character maps are not ASCII
compatible. In order to build locales using these character maps, and
have localedef exit with a status of 0, we add new option to localedef
to disable or enable specific warnings. The options are --no-warnings
and --warnings, to disable and enable specific warnings respectively.
The options take a comma-separated list of warning names. The warning
names are taken directly from the generated warning.  When a warning
that can be disabled is issued it will print something like this: foo is
not defined [--no-warnings=foo]

For the initial implementation we add two controllable warnings; first
'ascii' which is used by the localedata installation makefile target to
install SHIFT_JIS and SHIFT_JISX0213-using locales without error; second
'intcurrsym' which allows a program to use a non-standard international
currency symbol without triggering a warning.  The 'intcurrsym' is
useful in the future if country codes are added that are not in our
current ISO 4217 list, and the user wants to avoid the warning. Having
at least two warnings to control gives an example for how the changes
can be extended to more warnings if required in the future.

These changes allow ja_JP.SHIFT_JIS and ja_JP.SHIFT_JISX0213 to be
compiled without warnings using --no-warnings=ascii. The
localedata/Makefile $(INSTALL-SUPPORTED-LOCALES) target is adjusted to
automatically add `--no-warnings=ascii` for such charmaps, and likewise
localedata/gen-locale.sh is adjusted with similar logic.

v2: Bring verbose, be_quiet, and all warning control booleans into
record-status.c, and compile this object file to be used by locale,
iconv, and localedef. Any users include record-status.h.
v3: Fix an instance of boolean coercion in set_warning().

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