[gtk+] Add missing debug keys to the docs

[Matthias Clasen <matthiasc src gnome org>]

commit adc780f2b843e7bd0900a68523dc3e745c18abb4
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Jan 10 00:09:25 2018 -0500

    Add missing debug keys to the docs
    
    Several values for GDK_DEBUG were missing from the docs.

 docs/reference/gtk/running.sgml |   32 ++++++++++++++++++++++++++++----
 1 files changed, 28 insertions(+), 4 deletions(-)
---
diff --git a/docs/reference/gtk/running.sgml b/docs/reference/gtk/running.sgml
index bc0b981..3d042a0 100644
--- a/docs/reference/gtk/running.sgml
+++ b/docs/reference/gtk/running.sgml
@@ -291,10 +291,6 @@ nevertheless.
       <listitem><para>Information about cursor objects (only win32)</para></listitem>
     </varlistentry>
     <varlistentry>
-      <term>dnd</term>
-      <listitem><para>Information about drag-and-drop</para></listitem>
-    </varlistentry>
-    <varlistentry>
       <term>eventloop</term>
       <listitem><para>Information about event loop operation (mostly Quartz)</para></listitem>
     </varlistentry>
@@ -306,6 +302,34 @@ nevertheless.
       <term>nograbs</term>
       <listitem><para>Turn off all pointer and keyboard grabs</para></listitem>
     </varlistentry>
+    <varlistentry>
+      <term>frames</term>
+      <listitem><para>Information about the frame clock</para></listitem>
+    </varlistentry>
+    <varlistentry>
+      <term>settings</term>
+      <listitem><para>Information about xsettings</para></listitem>
+    </varlistentry>
+    <varlistentry>
+      <term>selection</term>
+      <listitem><para>Information about selections</para></listitem>
+    </varlistentry>
+    <varlistentry>
+      <term>clipboard</term>
+      <listitem><para>Information about clipboards</para></listitem>
+    </varlistentry>
+    <varlistentry>
+      <term>dnd</term>
+      <listitem><para>Information about drag-and-drop</para></listitem>
+    </varlistentry>
+    <varlistentry>
+      <term>opengl</term>
+      <listitem><para>Information about OpenGL</para></listitem>
+    </varlistentry>
+    <varlistentry>
+      <term>vulkan</term>
+      <listitem><para>Information about Vulkan</para></listitem>
+    </varlistentry>
 
   </variablelist>
   The special value <literal>all</literal> can be used to turn on all