Comprehensively rename to Mutter

Code:
All references in the code not related to themes, keybindings, or
GConf were changed from 'metacity' to 'mutter'. This includes, among other
things, strings, comments, the atoms used in the message protocol, and
the envvars used for debugging. The GConf schema file was reduced to
the 3 settings new to mutter.

The overall version was brought up to 2.27 to match current gnome.

Structure:
All files named '*metacity*' were renamed '*mutter*' with appropriate
changes in the automake system.  Files removed are
doc/creating_themes, src/themes, doc/metacity-theme.dtd,
metacity.doap.  These files will eventually end up in an external
gnome-wm-data module.

Installation location:
On the filesystem the mutter-plugindir was change from
$(libdir)/metacity/plugins/clutter to just $(libdir)/mutter/plugins.
The mutter-plugins.pc.in reflects these changes.

Note:
mutter.desktop.in and mutter-wm.desktop both continue to have
X-GNOME-WMSettingsModule=metacity set.  This allows
gnome-control-center to continue using libmetacity.so for
configuration.  This is fine since most the general keybindings and wm
settings are being read from /apps/metacity/* in gconf.

src/core/prefs.c

@@ -1,6 +1,6 @@
 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
 
-/* Metacity preferences */
+/* Mutter preferences */
 
 /* 
  * Copyright (C) 2001 Havoc Pennington, Copyright (C) 2002 Red Hat Inc.
@@ -57,7 +57,7 @@
 #define KEY_TERMINAL_DIR "/desktop/gnome/applications/terminal"
 #define KEY_TERMINAL_COMMAND KEY_TERMINAL_DIR "/exec"
 
-#define KEY_OVERLAY_KEY "/apps/metacity/general/overlay_key"
+#define KEY_OVERLAY_KEY "/apps/mutter/general/overlay_key"
 #define KEY_SCREEN_BINDINGS_PREFIX "/apps/metacity/global_keybindings"
 #define KEY_WINDOW_BINDINGS_PREFIX "/apps/metacity/window_keybindings"
 #define KEY_LIST_BINDINGS_SUFFIX "_list"
@@ -65,11 +65,11 @@
 #define KEY_WORKSPACE_NAME_PREFIX "/apps/metacity/workspace_names/name_"
 
 #ifdef WITH_CLUTTER
-#define KEY_CLUTTER_DISABLED "/apps/metacity/general/clutter_disabled"
-#define KEY_CLUTTER_PLUGINS  "/apps/metacity/general/clutter_plugins"
+#define KEY_CLUTTER_DISABLED "/apps/mutter/general/clutter_disabled"
+#define KEY_CLUTTER_PLUGINS  "/apps/mutter/general/clutter_plugins"
 #endif
 
-#define KEY_LIVE_HIDDEN_WINDOWS "/apps/metacity/general/live_hidden_windows"
+#define KEY_LIVE_HIDDEN_WINDOWS "/apps/mutter/general/live_hidden_windows"
 
 #define KEY_NO_TAB_POPUP "/apps/metacity/general/no_tab_popup"
 
@@ -328,7 +328,7 @@ typedef struct
 
 /* FIXMEs: */
 /* @@@ Don't use NULL lines at the end; glib can tell you how big it is */
-/* @@@ /apps/metacity/general should be assumed if first char is not / */
+/* @@@ /apps/mutter/general should be assumed if first char is not / */
 /* @@@ Will it ever be possible to merge init and update? If not, why not? */
 
 static MetaEnumPreference preferences_enum[] =
@@ -429,13 +429,13 @@ static MetaBoolPreference preferences_bool[] =
       FALSE,
     },
 #ifdef WITH_CLUTTER
-    { "/apps/metacity/general/clutter_disabled",
+    { "/apps/mutter/general/clutter_disabled",
       META_PREF_CLUTTER_DISABLED,
       &clutter_disabled,
       FALSE,
     },
 #endif
-    { "/apps/metacity/general/live_hidden_windows",
+    { "/apps/mutter/general/live_hidden_windows",
       META_PREF_LIVE_HIDDEN_WINDOWS,
       &live_hidden_windows,
       FALSE,
@@ -1028,6 +1028,7 @@ meta_prefs_remove_listener (MetaPrefsChangedFunc func,
 /* @@@ again, use glib's ability to tell you the size of the array */
 static gchar *gconf_dirs_we_are_interested_in[] = {
   "/apps/metacity",
+  "/apps/mutter",
   KEY_TERMINAL_DIR,
   KEY_GNOME_ACCESSIBILITY,
   "/desktop/gnome/peripherals/mouse",
@@ -1243,7 +1244,7 @@ change_notify (GConfClient    *client,
 #endif
   else
     {
-      meta_topic (META_DEBUG_PREFS, "Key %s doesn't mean anything to Metacity\n",
+      meta_topic (META_DEBUG_PREFS, "Key %s doesn't mean anything to Mutter\n",
                   key);
     }