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/setup.js

@@ -2,10 +2,13 @@
 
 var winston = require('winston');
 var async = require('async');
+var path = require('path');
+var nconf = require('nconf');
 
 var install = require('../../install/web').install;
 
-function setup() {
+function setup(initConfig) {
+	var paths = require('./paths');
 	var install = require('../install');
 	var build = require('../meta/build');
 	var prestart = require('../prestart');
@@ -17,9 +20,19 @@ function setup() {
 	console.log('\nThis looks like a new installation, so you\'ll have to answer a few questions about your environment before we can proceed.');
 	console.log('Press enter to accept the default setting (shown in brackets).');
 
+	install.values = initConfig;
+
 	async.series([
 		install.setup,
-		prestart.loadConfig,
+		function (next) {
+			var configFile = paths.config;
+			if (nconf.get('config')) {
+				configFile = path.resolve(paths.baseDir, nconf.get('config'));
+			}
+
+			prestart.loadConfig(configFile);
+			next();
+		},
 		build.buildAll,
 	], function (err, data) {
 		// Disregard build step data