Misc fixes and improvements (#6143)

* `setup` command fixes and improvements

- Enable using the `./nodebb setup` command for auto-setup with a JSON argument
- Change CLI so package-install and dependency install are separate steps
- Fix #6142

* Prevent compiling templates multiple times

- Multiple requests for same template get pooled
- Hopefully fixes the "templateFunction is not a function" error which happens if site is restarted during high-traffic times

* More helpful upgrade template

src/cli/paths.js

@@ -6,10 +6,12 @@ var baseDir = path.join(__dirname, '../../');
 var loader = path.join(baseDir, 'loader.js');
 var app = path.join(baseDir, 'app.js');
 var pidfile = path.join(baseDir, 'pidfile');
+var config = path.join(baseDir, 'config.json');
 
 module.exports = {
 	baseDir: baseDir,
 	loader: loader,
 	app: app,
 	pidfile: pidfile,
+	config: config,
 };