error handler for deprecated cms

1. add this to your composer.json, extra section:

   {
       "source": "vendor/studioartcz/sentry/plugins",
       "destination": "plugins",
       "debug": "true"
   }
   

2. type: composer require studioartcz/sl_sentry dev-master

3. add ignored files (.gitignore):

   # composer plugins
   plugins/extend/composer
   plugins/extend/sentry
   plugins/common/sentry
   

4. done