Update optimer and fleetup javascript (#695)

* Split out moment duration formatter

* Replace fleetup timer js

* Replace optimer js

* Remove obsolete countdown.js library

* Remove unused dateformat.js references

* Remove obsolete dateformat library

stock/static/js/timers.js

@@ -0,0 +1,15 @@
+/**
+* Get a duration string like countdown.js
+* e.g. "1y 2d 3h 4m 5s"
+* @param duration moment.duration
+*/
+function getDurationString(duration) {
+    var out = "";
+    if (duration.years()) {
+        out += duration.years() + 'y ';
+    }
+    if (duration.days()) {
+        out += duration.days() + 'd ';
+    }
+    return out + duration.hours() + "h " + duration.minutes() + "m " + duration.seconds() + "s";
+}