Add grammar-check function into TinyMCE web form

1. Set up a self-hosted LanguageTool server, download ngrams and make sure it will remain stable & online.
2. Integrate the server into a TinyMCE web form in order to add grammar-check functionality.
3. Set up cronjob on server for regular ngram updates.
4. Move server into cloud in case bottleneck occurs and/or speed is impaired.