Add deprecation warning to release-1.4 (#4756)

* Add Version Selector to v1.4

* upgrade to newer header

* change include_cached to include

* move head.html to correct location

* remove seo

* add footer-scripts.html

* turn on global nav

* fix docs nav link

* Add deprecation warning to release-1.4

* remove warning from index.html

* add newlines

_includes/head.html

@@ -7,6 +7,7 @@
 	<link rel="stylesheet" href="/css/styles.css"/>
 	<link rel="stylesheet" href="/css/jquery-ui.min.css">
 	<link rel="stylesheet" href="/css/sweetalert.css">
+	{% if page.deprecated %}<link rel="stylesheet" type="text/css" href="/css/deprecation-warning.css">{% endif %}
 	{% if page.class == "gridPage" %}<link rel="stylesheet" href="/css/gridpage.css">{% endif %}
 	<script src="/js/jquery-2.2.0.min.js"></script>
 	<script src="/js/jquery-ui.min.js"></script>