Re-add hook just removed; compose templates are so scattered, there is nowhere a plugin can add output to the bottom of the compose page except to output its own template on this hook -- must make sure plugins NEVER output directly here without using the template API (it is possible a plugin could slip this by us). Steve did his best with converting the compose page to templates, but it's a pretty big mess, with template chunks and still a lot of output coming directly from compose.php, especially things like the form tags and misc formatting - this must be cleaned out.

src/compose.php

@@ -1308,6 +1308,8 @@ function showInputForm ($session, $values=false) {
         $oTemplate->display('compose_newwin_close.tpl');
     }
 
+    do_hook('compose_bottom', $null);
+
     $oErrorHandler->setDelayedErrors(false);
     $oTemplate->display('footer.tpl');
 }