[Web] Fix log line handling

[Web] Add mailcow UI logs
[Web] Changes to _SESSION['return'] logic and logger (more to come)
[Web] Show last login
[Web, Postfix] Allow to disable sender check completely
[Web] Many minor fixes
[Web] Update some libs

data/web/css/mailcow.css

@@ -138,4 +138,12 @@ nav .glyphicon {
 }
 .bootstrap-select.btn-group .no-results {
   display: none;
-}
+}
+.dropdown-desc {
+  display: block;
+  padding: 3px 10px;
+  clear: both;
+  font-weight: bold;
+  color: #5a5a5a;
+  white-space: nowrap;
+}