Improve the graphics toolkit detection code so that properly

identifies situations where its restricted by open_basedir.

We now track more informatoin about the toolkit including the version
and any errors we encountered while doing the detection so that we can
provide more info downstream.  This makes graphics::detect_toolkits()
a little heavier, but that's ok because it should not be called very
often.

In the process, refactor the controller and view hierarchy so that
it's a little more straightforward in the code.

Fixes ticket #616.

modules/gallery/views/admin_graphics_none.html.php

@@ -2,6 +2,6 @@
 <div id="none" class="gBlock">
   <h3 class="gWarning"> <?= t("No Active Toolkit") ?> </h3>
   <p>
-    <?= t("We were unable to detect a graphics program.  You must install one of the toolkits below in order to many Gallery features.") ?>
+    <?= t("We were unable to detect a graphics program.  You must install one of the toolkits below in order to use many Gallery features.") ?>
   </p>
 </div>