Add a lock button widget

This is a special-purpose button that can be used together with
GPermission objects to control the sensitivity of system settings.

Suitable permission objects can e.g. be obtained from PolicyKit.

http://bugzilla.gnome.org/show_bug.cgi?id=626457

docs/reference/gtk/Makefile.am

@@ -296,6 +296,9 @@ HTML_IMAGES = \
 	$(srcdir)/images/label.png					\
 	$(srcdir)/images/link-button.png				\
 	$(srcdir)/images/list-and-tree.png				\
+	$(srcdir)/images/lockbutton-locked.png				\
+	$(srcdir)/images/lockbutton-unlocked.png			\
+	$(srcdir)/images/lockbutton-sorry.png				\
 	$(srcdir)/images/menubar.png					\
 	$(srcdir)/images/messagedialog.png				\
 	$(srcdir)/images/multiline-text.png				\

docs/reference/gtk/gtk-docs.sgml

@@ -115,6 +115,7 @@
       <xi:include href="xml/gtkscalebutton.xml" />
       <xi:include href="xml/gtkvolumebutton.xml" />
       <xi:include href="xml/gtkswitch.xml" />
+      <xi:include href="xml/gtklockbutton.xml" />
     </chapter>
 
     <chapter id="NumericEntry">

docs/reference/gtk/gtk3-sections.txt

@@ -7048,3 +7048,25 @@ GTK_APP_CHOOSER_WIDGET_GET_CLASS
 GtkAppChooserWidgetPrivate
 gtk_app_chooser_widget_get_type
 </SECTION>
+
+<SECTION>
+<FILE>gtklockbutton</FILE>
+<TITLE>GtkLockButton</TITLE>
+GtkLockButton
+
+gtk_lock_button_new
+gtk_lock_button_get_permission
+gtk_lock_button_set_permission
+
+<SUBSECTION Standard>
+GtkLockButtonClass
+GTK_TYPE_LOCK_BUTTON
+GTK_LOCK_BUTTON
+GTK_IS_LOCK_BUTTON
+GTK_LOCK_BUTTON_CLASS
+GTK_IS_LOCK_BUTTON_CLASS
+GTK_LOCK_BUTTON_GET_CLASS
+<SUBSECTION Private>
+gtk_lock_button_get_type
+GtkLockButtonPrivate
+</SECTION>

docs/reference/gtk/gtk3.types

@@ -92,6 +92,7 @@ gtk_label_get_type
 gtk_layout_get_type
 gtk_link_button_get_type
 gtk_list_store_get_type
+gtk_lock_button_get_type
 gtk_menu_bar_get_type
 gtk_menu_get_type
 gtk_menu_item_get_type

docs/reference/gtk/visual_index.xml

@@ -51,6 +51,9 @@
   <link linkend="GtkLinkButton">
     <inlinegraphic fileref="link-button.png" format="PNG"></inlinegraphic>
   </link>
+  <link linkend="GtkLockButton">
+    <inlinegraphic fileref="lockbutton.png" format="PNG"></inlinegraphic>
+  </link>
   <link linkend="GtkMenuBar">
     <inlinegraphic fileref="menubar.png" format="PNG"></inlinegraphic>
   </link>