Add a theme-stats command

Prints usage counters for all themes.

bin/noblogs.in

@@ -186,6 +186,25 @@ function do_set_theme($args) {
     }
 }
 
+// 'theme-stats': Prints statistics on theme usage for all local blogs.
+function do_theme_stats($args) {
+    $counters = array();
+    foreach (noblogs_get_local_blog_objects() as $blog) {
+        switch_to_blog($blog->blog_id);
+        $theme = get_option('template');
+        if ($theme) {
+            if (in_array($theme, $counters)) {
+                $counters[$theme]++;
+            } else {
+                $counters[$theme] = 1;
+            }
+        } 
+    }
+    foreach ($counters as $theme => $n) {
+        echo("{$theme} {$n}\n");
+    }
+}
+
 // 'dump-shards': Print a JSON dictionary representing the full map
 // of backend -> blogs database mappings.
 function do_dump_shards($args) {