Gio::Action: Fix activate(const Glib::Variant<T_Value>& value)

* gio/src/action.hg: Make activate(const Glib::Variant<T_Value>& value)
call activate_variant(). Fix a typo in a comment. Bug #722896 comment 3.
Add Gio::Notification

* gio/src/application.hg: Add send_notification(), withdraw_notification().
* gio/src/notification.[hg|ccg]: New files.
* gio/src/filelist.am: Add notification.hg.
* gio/giomm.h: Add giomm/notification.h.
* tools/m4/convert_gio.m4: Add conversions between GNotification and
Gio::Notification. Bug #722896.
OptionContext: Add API documentation based on the C docs.

* glib/src/optioncontext.hg: Add class overview documentation
  based on the C documentation, but reworded to match our C++ API.
  This should now provide some clue about where to start other
  than with our (well hidden) example code.
* glib/src/optiongroup.hg: Add documentation for the add_entry*()
  methods.
OptionContext: TODO comment discussing g_option_context_parse_strv() and win32.
Gio::Action: Add parse_detailed_name() and parse_detailed_name_variant()

* gio/src/action.hg: Add parse_detailed_name() and
parse_detailed_name_variant().
* tools/m4/initialize_glib.m4: Add _INITIALIZATION of Glib::ustring&
from gchar*.
gmmproc: Don't change NULL to 0 in docs, when it's part of a longer name

* tools/pm/DocsParser.pm: Don't change NULL to 0, TRUE to true,
FALSE to false, when they are part of a longer name.
Regenerate gio_methods.defs

* gio/src/gio_methods.defs: Some inconsistent parameter names have been fixed
in glib/gio header files.
Fix some doxygen warnings

* gio/src/action.hg:
* gio/src/actionmap.hg:
* gio/src/dbusconnection.hg:
* gio/src/dbusproxy.hg:
* gio/src/file.hg:
* gio/src/fileinfo.hg:
* gio/src/menuitem.hg:
* gio/src/mount.hg:
* gio/src/settings.hg:
* gio/src/simpleaction.hg:
* gio/src/threadedsocketservice.hg:
* glib/glibmm/base64.h:
* glib/glibmm/refptr.h:
* glib/src/variant.hg: Fix some warnings in doxygen.log.
Gio::MenuModel: Add signal_items_changed()

* gio/src/menumodel.hg:  Wrap the "items-changed" signal.
gio/src/fileattributeinfo.hg: Remove NO_GTYPE from _WRAP_ENUMs

* gio/src/fileattributeinfo.hg: A comment said that NO_GTYPE was necessary
because gmmproc generated the wrong name for the _get_type() functions.
That was fixed in tools/m4/base.m4 on 2009-03-19 by commit
https://git.gnome.org/browse/glibmm/commit/?id=2343e537edae800a2969d57ec49cb58585b3de22
Probably many more NO_GTYPE can be removed in glibmm.
Merge branch 'master' of git://git.gnome.org/glibmm

Conflicts (hopefully resolved):
	glib/glibmm/base64.h
JOHNE - Add support for a newly introduced class (Gio::Notification)