Feature migrations up/down (#270)

* Migrations up down

* Add forum model

* Syntactic sugar for db structure changes

* Refactor migrations with $up & $down

* Fix migrations upgrade and downgrade

+ Add option to disable auto migrate

* Add migrate:to command

Usage: php aac migrate:to x (x - database version)

* Show error when mail is not enabled

* Fixes regarding to init.php

* Add migrate command to manually upgrade db, incase auto migrate is disabled

* Fixed rest of the migrations

* Limit max version of database

* Don't allow minus number

* Option to clear specified plugin settings by name

* Version is required

* Fix PHPStan errors

* Unset $up after migration, to prevent executing same migration twice

* Add database version to output

* This is not needed

* Update 5.php

* Set database_auto_migrate on install

* Set blank & color only if current db version supports it

* Fix duplicate function declaration

system/migrations/17-menu.sql

@@ -0,0 +1,11 @@
+CREATE TABLE `myaac_menu`
+(
+	`id` INT(11) NOT NULL AUTO_INCREMENT,
+	`template` VARCHAR(255) NOT NULL,
+	`name` VARCHAR(255) NOT NULL,
+	`link` VARCHAR(255) NOT NULL,
+	`category` INT(11) NOT NULL DEFAULT 1,
+	`ordering` INT(11) NOT NULL DEFAULT 0,
+	`enabled` INT(1) NOT NULL DEFAULT 1,
+	PRIMARY KEY (`id`)
+) ENGINE=InnoDB DEFAULT CHARACTER SET=utf8;