* tools/defs_gen/docextract.py: Accept underscores in property names
  and signal names.
* tools/pm/DocsParser.pm: Accept underscores in property names and in
  signal names with gi-docgen syntax.
  Convert enumerator names with gi-docgen syntax.

Ignore -Winconsistent-dllimport warning from clang in wrap_init.cc

Closes #119

See merge request !63

One still might want to try to build or use glibmm built with NMake, so define
these as appropriate for Visual Studio, in case glibmmconfig.h is not
processed with Meson.

clang-cl also defines _MSC_VER like Visual Studio, but uses GCC-style
directives for silencing warnings for inconsistent dllimport directives
(that is outside of glibmm's control), so we update the previous commit
to now first check for __GNUC__ and __clang__, and then _MSC_VER.

Silences warnings for inconsistent dllimport directives for clang-cl as
well, in addition to GCC-style CLang.

It's a templatized in-header implementation, so we can just leave out
the GLIBMM_API decoration. Silences a warning from CLang/clang-cl.

Remove unnecessary forward class declarations.
Clang 18 on Windows does not like them.

Clang 18 does not consider NULL good enough in calls to g_object_get().

The clang compiler on Windows warns like MSVC, when declarations
in wrap_init.cc lacks __declspec(dllimport).
Compare d6614725
Fixes #119

clang 19.0.0 does not like the overload that takes a
const std::basic_string<guchar>&. This overload should have been removed
16 years ago by commit 84135b93.
It can't be removed completely now, because that would break ABI.
Remove as much as possible.
Fixes #118

* configure.ac:
* meson.build: Require glib-2.0 >= 2.79.2.
* gio/src/application.hg: Add get/set/property_version().
* gio/src/applicationcommandline.[ccg|hg]: Add done().
Use g_application_command_line_print/printerr_literal() in print/printerr().
* gio/src/dbusmessage.hg: Add get_arg0_path().
* gio/src/socket.hg: Add receive_bytes() and receive_bytes_from().
* glib/glibmm/utility.h: Add convert_const_gchar_ptr_to_dbus_object_path_string().
* glib/src/datetime.hg: Add create_from_local_usec(), create_from_utc_usec()
and to_unix_usec().
* tools/m4/convert_glib.m4: Add conversion for Glib::DBusObjectPathString.

using glib files from glib 2.80.0.

* glib/src/convert.[ccg|hg]: Add wide_from_utf8() and wide_to_utf8().
* tests/glibmm_ustring_make_valid/main.cc: Test the new functions.

Based on Chris Vine's patch in issue 9.

Fixes #9

Make a note to users that Visual Studio 2019 or later is recommended if
building against libsigc++-3.6.x or later as warnings are being
generated as C++-17 support is not that well done in 2017 when building
against libsigc++-3.6.x or later.

This way, one may opt to pass in a base include|libpath|tools_path, plus
conrresponding paths to GLib and libsigc++ as needed to assist NMake in
finding the headers, .lib's and tools from the dependencies as needed so
that building things with NMake is made easier with more flexibility.

ustring: TODO to avoid copies from operator string + C++20 move from outstreams

See merge request !62

Our conversion operator to std::string always returns a copy but that is
wasteful when it could be a const& reference or moved-out from an rvalue
– especially bad since conversions can occur silently & harm performance
without users realising. We can split to const&/&& overloads at next ABI

C++20 adds `ostream.str() &&` for rvalue `this`, which will move out the
stream's owned string. We can use that once we are on C++20 to avoid the
extra copy of the string (although we do then copy that AGAIN via GLib!)

If a signal handler deletes a Dispatcher, a DispatchNotifier
can be deleted while its pipe_io_handler() method is executing.
Stop its execution if this happens.

Fixes #116

GdkDmabufTextureBuilder contains functions that return unsigned int.

using glib files from glib 2.78.0.

Glib::ustring: Add a std::hash<> specialization.

Closes #16

See merge request !61

So people can use it as a key for std::unordered_map and
std::unordered_set. Originally proposed by Murray Cumming.
Add tests/glibmm_ustring_hash.
Fixes #16

and change Gtk::Bin to Gtk::Widget. Gtk::Bin does not exist in gtkmm4.

* configure.ac:
* meson.build: Require glib-2.0 >= 2.77.0.
* gio/src/actionmap.hg: _IGNORE(g_action_map_remove_action_entries).
* gio/src/resolver.hg: Add set/get/property_timeout().
* glib/glibmm/ustring.[cc|h]: Add ustring::truncate_middle().

using glib files from glib 2.77.0.

See gtkmm#140

Convert the README.win32 file into MarkDown format so that it is easier on the
eye for formatting, and convert it to UNIX line endings.  Also update the info
that is in there to reflect the current situation on Visual Studio better.

Accept "+" in GTK_ALIGN_BASELINE = GTK_ALIGN_CENTER + 1,

tests: Test for /etc/passwd instead of /etc/fstab

See merge request !60

/etc/fstab is not guaranteed to exist on modern Linux distros