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.

plugins/Favorite/lib/favcommand.php

@@ -0,0 +1,52 @@
+<?php
+
+class FavCommand extends Command 
+{ 
+    var $other = null; 
+ 
+    function __construct($user, $other) 
+    { 
+        parent::__construct($user); 
+        $this->other = $other; 
+    } 
+ 
+    function handle($channel) 
+    { 
+        $notice = $this->getNotice($this->other); 
+ 
+        $fave            = new Fave(); 
+        $fave->user_id   = $this->user->id; 
+        $fave->notice_id = $notice->id; 
+        $fave->find(); 
+ 
+        if ($fave->fetch()) { 
+            // TRANS: Error message text shown when a favorite could not be set because it has already been favorited. 
+            $channel->error($this->user, _('Could not create favorite: Already favorited.')); 
+            return; 
+        } 
+ 
+        $fave = Fave::addNew($this->user->getProfile(), $notice); 
+ 
+        if (!$fave) { 
+            // TRANS: Error message text shown when a favorite could not be set. 
+            $channel->error($this->user, _('Could not create favorite.')); 
+            return; 
+        } 
+ 
+        // @fixme favorite notification should be triggered 
+        // at a lower level 
+ 
+        $other = User::getKV('id', $notice->profile_id); 
+ 
+        if ($other && $other->id != $this->user->id) { 
+            if ($other->email && $other->emailnotifyfav) { 
+                mail_notify_fave($other, $this->user, $notice); 
+            } 
+        } 
+ 
+        $this->user->blowFavesCache(); 
+ 
+        // TRANS: Text shown when a notice has been marked as favourite successfully. 
+        $channel->output($this->user, _('Notice marked as fave.')); 
+    } 
+}

plugins/Favorite/lib/threadednoticelistfavesitem.php

@@ -0,0 +1,80 @@
+<?php
+/**
+ * GNU Social - a federating social network
+ * Copyright (C) 2014, Free Software Foundation, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('GNUSOCIAL')) { exit(1); }
+
+/**
+ * Placeholder for showing faves...
+ */
+class ThreadedNoticeListFavesItem extends NoticeListActorsItem
+{
+    function getProfiles()
+    {
+        $faves = Fave::byNotice($this->notice);
+        $profiles = array();
+        foreach ($faves as $fave) {
+            $profiles[] = $fave->user_id;
+        }   
+        return $profiles;
+    }
+
+    function magicList($items)
+    {
+        if (count($items) > 4) {
+            return parent::magicList(array_slice($items, 0, 3));
+        } else {
+            return parent::magicList($items);
+        }   
+    }
+
+    function getListMessage($count, $you)
+    {
+        if ($count == 1 && $you) {
+            // darn first person being different from third person!
+            // TRANS: List message for notice favoured by logged in user.
+            return _m('FAVELIST', 'You like this.');
+        } else if ($count > 4) {
+            // TRANS: List message for when more than 4 people like something.
+            // TRANS: %%s is a list of users liking a notice, %d is the number over 4 that like the notice.
+            // TRANS: Plural is decided on the total number of users liking the notice (count of %%s + %d).
+            return sprintf(_m('%%s and %d others like this.',
+                              '%%s and %d others like this.',
+                              $count),
+                           $count - 3);
+        } else {           
+            // TRANS: List message for favoured notices.
+            // TRANS: %%s is a list of users liking a notice.
+            // TRANS: Plural is based on the number of of users that have favoured a notice.
+            return sprintf(_m('%%s likes this.',
+                              '%%s like this.',
+                              $count),
+                           $count);
+        }                  
+    }
+
+    function showStart()
+    {
+        $this->out->elementStart('li', array('class' => 'notice-data notice-faves'));
+    }   
+
+    function showEnd()
+    {
+        $this->out->elementEnd('li');
+    }   
+}

plugins/Favorite/lib/threadednoticelistinlinefavesitem.php

@@ -0,0 +1,34 @@
+<?php
+/**
+ * GNU Social - a federating social network
+ * Copyright (C) 2014, Free Software Foundation, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('GNUSOCIAL')) { exit(1); }
+
+// @todo FIXME: needs documentation.
+class ThreadedNoticeListInlineFavesItem extends ThreadedNoticeListFavesItem
+{
+    function showStart()
+    {
+        $this->out->elementStart('div', array('class' => 'notice-faves'));
+    }
+
+    function showEnd()  
+    {
+        $this->out->elementEnd('div');
+    }
+}