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

install/steps/5-database.php

@@ -40,6 +40,7 @@ if(!$error) {
 	$configToSave['gzip_output'] = false;
 	$configToSave['cache_engine'] = 'auto';
 	$configToSave['cache_prefix'] = 'myaac_' . generateRandomString(8, true, false, true);
+	$configToSave['database_auto_migrate'] = true;
 
 	if(!$error) {
 		$content = '';