Something is borked with the doc build.  This seems to fix it, but it
is not clear why.

It seems like introspection encourages violating the C standard.
It seems to want private symbols that start with _.

Somehow, without that, the build breaks in docs.

(To actually see the break, manually remove docs/xml before building.)

build-sys: fix out-of-source build

See merge request !6

See #19.

/usr/x86_64-w64-mingw32/sys-root/mingw/include/glib-2.0/glib/gstdio.h:137:31: note: expected 'GStatBuf *' {aka 'struct _stat64 *'} but argument is of type 'struct stat *'
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

GMTOFF() is unused for a long while.

Fixes:
gsf-timestamp.c:103:15: warning: 'gmt_to_local_win32' defined but not
used
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Use glib printf-variants functions that are gnuc-compliant.
Fixes win32 build warnings:
 warning: unknown conversion type character 'l' in format
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

We don't want to miss anything later.

Introduce a gsf-priv unit, and implement our own property/params
functions. Note: there are probably better ways of doing this.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

2.36 was released 7 years ago, available in Debian old stable and
RHEL/CentOS 7.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

It's used outside libgsf, so we cannot remove it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Edited by MW to avoid g_autoptr.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

This must be set before the first write in order to take effect.

build: Allow building with gettext ≥ 0.20

See merge request !3

The use of AM_GNU_GETTEXT_VERSION in configure.ac instructs autopoint to
copy po/Makefile.in.in from the exact gettext version. It is fine if the
version of gettext installed on the system has the same minor version
number with the requested version, but it fails if you have a newer
version of gettext because of the mismatch between autoconf macros and
Makefile.in.in.

  *** error: gettext infrastructure mismatch: using a Makefile.in.in
  from gettext version 0.19 but the autoconf macros are from gettext
  version 0.20

Instead of specifying the exact version with AM_GNU_GETTEXT_VERSION, we
can use AM_GNU_GETTEXT_REQUIRE_VERSION to ask autopoint to simply use
the gettext version installed on the system to prevent the mismatch.

This also bumps the version requirement on gettext to 0.19.6 because
AM_GNU_GETTEXT_REQUIRE_VERSION was added in this version.