EogThumbnail: Load thumbnail frame from a GResource

Also optimize the frame's filesize.

data/pixmaps/Makefile.am

@@ -1,9 +1,4 @@
-pixmapsdir = $(pkgdatadir)/pixmaps
-
-pixmaps_DATA = \
+EXTRA_DIST = \
 	thumbnail-frame.png
 
-EXTRA_DIST = \
-	$(pixmaps_DATA)
-
 -include $(top_srcdir)/git.mk

src/eog-thumbnail.c

@@ -534,6 +534,8 @@ eog_thumbnail_init (void)
 	}
 
 	if (frame == NULL) {
-		frame = gdk_pixbuf_new_from_file (EOG_DATA_DIR "/pixmaps/thumbnail-frame.png", NULL);
+		frame = gdk_pixbuf_new_from_resource (
+				"/org/gnome/eog/ui/pixmaps/thumbnail-frame.png",
+				NULL);
 	}
 }

src/eog.gresource.xml

@@ -7,6 +7,7 @@
     <file compressed="true" preprocess="xml-stripblanks">eog-multiple-save-as-dialog.ui</file>
     <file compressed="true" preprocess="xml-stripblanks">eog-preferences-dialog.ui</file>
     <file compressed="true" preprocess="xml-stripblanks">eog-ui.xml</file>
+    <file>pixmaps/thumbnail-frame.png</file>
   </gresource>
 </gresources>