Tutorial 9: Web applications - init (#15)

* Init from MarekSuchanek/FPCourse

* Fix extension and intro

* Snap and Yesod just briefly

* Simple socket server/client

* Networking and templates

* Persistent and improvements

* WAI

* Low-level DB, list of frameworks

* Finalization and grammar fix

* Change examples... need more

* reviews

Author: MarekSuchanek