pluginified most of hasFave, getFaves and related calls

The code is now more event-driven when it comes to rendering notices
and their related HTML elements, since we can't have direct calls from
core to a plugin.

lib/activitymover.php has a function to move a Favorite activity which
will not happen now. The move must be pluginified and performed as an
event which plugins can catch on to.

lib/commandinterpreter.php

@@ -37,7 +37,7 @@ class CommandInterpreter
 
         $cmd = strtolower($cmd);
 
-        if (Event::handle('StartIntepretCommand', array($cmd, $arg, $user, &$result))) {
+        if (Event::handle('StartInterpretCommand', array($cmd, $arg, $user, &$result))) {
             switch($cmd) {
             case 'help':
                 if ($arg) {
@@ -231,18 +231,6 @@ class CommandInterpreter
                     }
                 }
                 break;
-            case 'fav':
-                if (!$arg) {
-                    $result = null;
-                } else {
-                    list($other, $extra) = $this->split_arg($arg);
-                    if ($extra) {
-                        $result = null;
-                    } else {
-                        $result = new FavCommand($user, $other);
-                    }
-                }
-                break;
             case 'nudge':
                 if (!$arg) {
                     $result = null;