Make colon copy and pasteable, fix #783

src/Whoops/Resources/css/whoops.base.css

@@ -230,10 +230,6 @@ header {
       font-weight: bold;
     }
 
-    .frame-line:before {
-      content: ":";
-    }
-
     .frame-code {
       padding: 5px;
       background: #303030;

src/Whoops/Resources/views/frame_list.html.php

@@ -11,7 +11,7 @@
 
     <div class="frame-file">
         <?php echo $frame->getFile() ? $tpl->breakOnDelimiter('/', $tpl->shorten($tpl->escape($frame->getFile()))) : '<#unknown>' ?><!--
-   --><span class="frame-line"><?php echo (int) $frame->getLine() ?></span>
+   --><span class="frame-line">:<?php echo (int) $frame->getLine() ?></span>
     </div>
   </div>
 <?php endforeach;