Everywhere: Add config and cache page

Add config database table and enable crud page.
Also add cache controller, model and view and routes for these pages.

Make the JavaScript display a message when changing the state of
development mode.

app/model/ConfigModel.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace App\Model;
+
+use App\Traits\Log;
+
+class ConfigModel extends Model {
+
+	use Log;
+
+	protected $table = 'config';
+	protected $sort = 'key';
+
+	public $title = "Config";
+
+	// Attribute rules
+	// Name | Type | Required | Filtered
+	public $rules = [
+		["key",              "text",      1, 0],
+		["value",            "text",      0, 0],
+		["log_id",           "text",      1, 1],
+	];
+}