Regenerate enums .defs.
Regenerate methods .defs.
Regenerated extra .defs files.
Regenerate docs.xml files.
3.15.2
Add class Gtk::CssSection and enum Gtk::CssSectionType

* .gitignore: Add csssection.[h|cc].
* gtk/gtkmm.h: Add csssection.h.
* gtk/src/filelist.am: Add csssection.hg.
* gtk/src/gtk_extra_objects.defs: Add GtkCssSection.
* gtk/src/csssection.[hg|ccg]: New files.
* tools/m4/convert_gtk.m4: Add conversions for CssSection and CssSectionType.
Gtk::CssProvider: Add CssProviderError and signal_parsing_error()

* gtk/src/cssprovider.[hg|ccg]: Add CssProviderError, signal_parsing_error()
and load_from_resource().
* gtk/src/gtk_signals.defs: Update with CssProvider::signal_parsing_error().
* gtk/src/gtk_signals.defs.patch: Change the type of parameter 'error' (p1) to
signal_parsing_error() handlers.
* tools/extra_defs_gen/generate_defs_gtk.cc:
Add get_defs(GTK_TYPE_CSS_PROVIDER).
* tools/m4/convert_gtk.m4: Add conversion for CssProviderError.
Add GtkSelectionData to gtk_extra_objects.defs

* gtk/src/gtk_extra_objects.defs: Add GtkSelectionData.
ScaleButton: Correct the constructor.

gtk_scale_button_new() does more than just call g_object_new() so
we cannot just assume that the parameters correspond to
GObject property names.
This has apparently been wrong from the start, many years ago.
Probably few people, if any, need to use this.
ScaleButton: Add a constructor without the icons.

Because gtk_scale_button_new() allows that to be NULL.
ScaleButton: Document the constructors.
Fix some Doxygen warnings

* gdk/gdkmm/general.h:
* gdk/src/pixbuf.hg:
* gtk/gtkmm/accelmap.h:
* gtk/src/application.hg:
* gtk/src/arrow.hg:
* gtk/src/button.hg:
* gtk/src/clipboard.hg:
* gtk/src/iconinfo.hg:
* gtk/src/menu.hg:
* gtk/src/menubutton.hg:
* gtk/src/plug.hg:
* gtk/src/recentaction.hg:
* gtk/src/scalebutton.hg:
* gtk/src/treeview.hg:
* gtk/src/uimanager.hg:
Correct parameter names in @param directives, remove extraneous @ and #,
change <xyz> to \<xyz\> when it shall not be interpreted by doxygen, etc.
Merge branch 'master' of git://git.gnome.org/gtkmm