show timestamps in local date/locale

this adds a helper script to rewrite all time elements with a proper
datetime attribute into the users locale via the browser
navigator.language.

collection, collection-post and chorus-collection-post templates now
include this script

static/js/localdate.js

@@ -0,0 +1,9 @@
+function toLocalDate(el) {
+	var d = new Date(el.getAttribute("datetime"));
+	el.textContent = d.toLocaleDateString(navigator.language || "en-US", { year: 'numeric', month: 'long', day: 'numeric' });
+}
+
+var $dates = document.querySelectorAll("time");
+for (var i=0; i < $dates.length; i++) {
+	toLocalDate($dates[i]);
+}

templates/chorus-collection-post.tmpl

@@ -90,6 +90,7 @@ article time.dt-published {
 		{{range .Collection.ExternalScripts}}<script type="text/javascript" src="{{.}}" async></script>{{end}}
 		{{if .Collection.Script}}<script type="text/javascript">{{.Collection.ScriptDisplay}}</script>{{end}}
 	{{end}}
+	<script src="/js/localdate.js"></script>
 	<script type="text/javascript">
 
 var pinning = false;

templates/collection-post.tmpl

@@ -70,6 +70,7 @@
 		{{range .Collection.ExternalScripts}}<script type="text/javascript" src="{{.}}" async></script>{{end}}
 		{{if .Collection.Script}}<script type="text/javascript">{{.Collection.ScriptDisplay}}</script>{{end}}
 	{{end}}
+	<script src="/js/localdate.js"></script>
 	<script type="text/javascript">
 
 var pinning = false;

templates/collection.tmpl

@@ -113,6 +113,7 @@
 	{{end}}
 	<script src="/js/h.js"></script>
 	<script src="/js/postactions.js"></script>
+	<script src="/js/localdate.js"></script>
 	<script type="text/javascript">
 var deleting = false;
 function delPost(e, id, owned) {