Add web front-end and fix API issues

node_modules/rxjs/dist/esm5/internal/observable/iif.js

@@ -0,0 +1,5 @@
+import { defer } from './defer';
+export function iif(condition, trueResult, falseResult) {
+    return defer(function () { return (condition() ? trueResult : falseResult); });
+}
+//# sourceMappingURL=iif.js.map