don't handle the tab key if the tag input is empty, so that the user …

…can tab on through a form

TODO

@@ -1,3 +1,5 @@
 * Update the autocomplete to use the new jQuery UI autocomplete widget. The 
 current one is deprecated, though still functional.
 
+* Add keyboard shortcuts for highlighting tags to remove them upon backspace.
+

example.html

@@ -10,7 +10,7 @@
 
     <link rel="stylesheet" type="text/css" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1/themes/flick/jquery-ui.css">
 	<link href="css/jquery.tagit.css" rel="stylesheet" type="text/css">
-	<!--<link href="css/tagit.ui-zendesk.css" rel="stylesheet" type="text/css">-->
+    <!--<link href="css/tagit.ui-zendesk.css" rel="stylesheet" type="text/css">-->
 
 	<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js" type="text/javascript" charset="utf-8"></script>
     <script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.12/jquery-ui.min.js" type="text/javascript" charset="utf-8"></script>

js/tag-it.js

@@ -108,10 +108,14 @@
 
                     // Comma/Space/Enter are all valid delimiters for new tags,
                     // except when there is an open quote or if setting allowSpaces = true.
+                    // Tab will also create a tag, unless the tag input is empty, in which case it isn't caught.
                     if (
                         event.which == $.ui.keyCode.COMMA ||
-                        event.which == $.ui.keyCode.TAB ||
                         event.which == $.ui.keyCode.ENTER ||
+                        (
+                            event.which == $.ui.keyCode.TAB &&
+                            self._tagInput.val() !== ''
+                        ) ||
                         (
                             event.which == $.ui.keyCode.SPACE &&
                             self.options.allowSpaces !== true &&