Update tutorials and improve second half of the semester

[MarekSuchanek]

Tutorials 6 - 12 should be improved, some can be merged and substituted by Elm (#23) as another way of functional programming - frontend oriented. It may require also a change in tutorials 3, 4, and 5.

Plan

• Tutorial 1 - just go through and update
• Tutorial 2 - just go through and update
• Tutorial 3 - text types (as evaluation is already there)
• Tutorial 4 - more information about advanced function
• Tutorial 5 - basic typeclasses and also start of IO monad, error handling
• Tutorial 6 - also performance, profiling and debugging
• Tutorial 7 - advanced typeclasses and transformers
• Tutorial 8 - webapp
• Tutorials 9, 10, 11 - Elm More Elm focused tutorials #23 (12 can be partly Elm - "follow ups and interesting FP stuff")

[MarekSuchanek]

I will continue on this in #30