include local.html file meant to define local analytics properties (#1612)

* include local.html file meant to define local analytics properties
include all specified local analytics properties in analytics events

* use new variable name jitsiDeploymentInfo to represent more general use as local deployment information collection

index.html

     <meta http-equiv="content-type" content="text/html;charset=utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <!--#include virtual="base.html" -->
+    <!--#include virtual="local.html" -->
     <script>
         window.indexLoadedTime = window.performance.now();
         console.log("(TIME) index.html loaded:\t", indexLoadedTime);

modules/analytics/analytics.js

                 if (group) {
                     permanentProperties.group = group;
                 }
+                /**
+                 * optionally include local deployment information,
+                 * window.jitsiDeploymentInfo defined outside of application
+                 * to use, override contents in local.html
+                **/
+                if (window.jitsiDeploymentInfo) {
+                    for (var key in window.jitsiDeploymentInfo) {
+                        permanentProperties[key] 
+                            = window.jitsiDeploymentInfo[key];
+                    }
+                }
 
                 analytics.addPermanentProperties(permanentProperties);
                 analytics.setAnalyticsHandlers(handlers);