Add base application

Simple class for basic application, we may move this to an other project.

The project structure should be:

```
./config
./config/config.(xml|php|ini|yml)
./files/
./files/cache/.git-keep
./files/testing/.git-keep
./web/index.php
./composer.json
```

Configuration should be:

```yaml
mode: production
debug: false
connections:
  default: { db_driver: …, db_name: …, db_user: …, db_password, …}
  mongodb: { … }
smtp: { … }
monolog: { … }
```

Index.php should be as simple as this:

```php
# @file index.php
use \AndyTruong\Application\BaseApplicatoin as App;
$app = new App($root = dirname(__DIR__));
$app->run();
```