use client?s mimetype as fallback for uploads

www/analytics/plugins/CoreHome/angularjs/piwikAppConfig.js

@@ -0,0 +1,9 @@
+angular.module('piwikApp.config', []);
+
+(function () {
+    var piwikAppConfig = angular.module('piwikApp.config');
+    // we probably want this later as a separate config file, till then it serves as a "bridge"
+    for (var index in piwik.config) {
+        piwikAppConfig.constant(index.toUpperCase(), piwik.config[index]);
+    }
+})();