Merging from MOODLE_16_STABLE:

Fix for MDL-8515: Prefixing chat messages with a slash should not hide the
user's name unless it's a special command we handle.

I completely removed the emoticon handling case, but it seems like it was
not needed for a long time now? Emoticons work just fine without it.

mod/chat/lib.php

@@ -572,9 +572,13 @@ function chat_format_message_manually($message, $courseid, $sender, $currentuser
 
     $options->para = false;
     $text = format_text($text, FORMAT_MOODLE, $options, $courseid);
+
     // And now check for special cases
+    $special = false;
+
     if (substr($text, 0, 5) == 'beep ') {
         /// It's a beep! 
+        $special = true;
         $beepwho = trim(substr($text, 5));
 
         if ($beepwho == 'all') {   // everyone
@@ -591,25 +595,19 @@ function chat_format_message_manually($message, $courseid, $sender, $currentuser
         } else {  //something is not caught?
             return false;
         }
-    } else if (substr($text, 0, 1) == ':') {              /// It's an MOO emote
-        $outinfo = $message->strtime;
-        $outmain = $sender->firstname.' '.substr($text, 1);
-
     } else if (substr($text, 0, 1) == '/') {     /// It's a user command
-
-        if (substr($text, 0, 4) == "/me ") {
+        if (trim(substr($text, 0, 4)) == '/me') {
+            $special = true;
             $outinfo = $message->strtime;
             $outmain = $sender->firstname.' '.substr($text, 4);
-        } else {
-            $outinfo = $message->strtime;
-            $outmain = $text;
         }
+    }
 
-    } else {                                          /// It's a normal message
+    if(!$special) {
         $outinfo = $message->strtime.' '.$sender->firstname;
         $outmain = $text;
     }
-     
+
     /// Format the message as a small table
 
     $output->text  = strip_tags($outinfo.': '.$outmain);