Show more links work with AJAX-retrieved HTML

Attachment_ajaxAction has been removed since AttachmentAction handles
AJAX calls splendidly.

lib/attachmentlistitem.php

@@ -159,7 +159,8 @@ class AttachmentListItem extends Widget
                     break;
 
                 case 'text/html':
-                    if (!empty($this->attachment->filename) && common_config('attachments', 'show_html')) {
+                    if (!empty($this->attachment->filename)
+                            && (StatusNet::isAjax() || common_config('attachments', 'show_html'))) {
                         // Locally-uploaded HTML. Scrub and display inline.
                         $this->showHtmlFile($this->attachment);
                         break;

lib/default.php

@@ -249,7 +249,7 @@ $default =
               'user_quota' => 50000000,
               'monthly_quota' => 15000000,
               'uploads' => true,
-              'show_html' => false,  // HTML representation for locally uploaded HTML attachments (oEmbed links etc.)
+              'show_html' => false,  // show (filtered) text/html attachments (and oEmbed HTML etc.). Doesn't affect AJAX calls.
               'show_thumbs' => true, // show thumbnails in notice lists for uploaded images, and photos and videos linked remotely that provide oEmbed info
               'process_links' => true, // check linked resources for embeddable photos and videos; this will hit referenced external web sites when processing new messages.
               ),

lib/router.php

@@ -218,10 +218,6 @@ class Router
                         array('action' => 'attachment'),
                         array('attachment' => '[0-9]+'));
 
-            $m->connect('attachment/:attachment/ajax',
-                        array('action' => 'attachment_ajax'),
-                        array('attachment' => '[0-9]+'));
-
             $m->connect('attachment/:attachment/thumbnail',
                         array('action' => 'attachment_thumbnail'),
                         array('attachment' => '[0-9]+'));