polishing examples
BigStep Call-by-name interpreter
small step call by value interpreter
all examples with interpreters
small step CBN interpreter with evaluation tree
small-step CBV with evaluation tree
mixed interpreter + examples
Merge branch 'master' of https://github.com/ilya-klyuchnikov/sll-meta-haskell into winter-school

Conflicts:
	DataUtil.hs
	Examples/Examples.hs
	Interpreters/SmallStepCBN.hs
tree interpreter is done (without support of TestEq-expressions)