dunai-examples: Conformance with style guide

[ivanperez-keera]

Description

Several files inside dunai-examples/ are not conformant with our own style guide. These are mainly in the examples directory.

Because the non-conformances may take quite some time to fix, I've decided to split #349 into smaller issues.

A quick search shows the following potential violations:

3 File structure, no blank lines at top
./list/BouncingBall.hs
./timetransform/TimeTransform.hs
./bouncingball/BouncingBall.hs
./testing.hs
./reversefrpzoo/wormholes/src/Data/MonadicStreamFunction/Wormhole.hs
./classicfrp/Test.hs
./classicfrp/GTest.hs

3.3 All Haskell files must include a copyright notice in a comment
bouncingball/BouncingBall.hs
classicfrp/GTest.hs
classicfrp/Test.hs
discrete/WXStep.hs
discrete/WXText.hs
keerahails/WXText.hs
list/BouncingBall.hs
paper/src/DunaiExamplesExtensibleAFRP.hs
paper/src/DunaiExamplesMonads.hs
paper/src/DunaiExamplesReactiveValues.hs
reversefrpzoo/wormholes/src/Data/MonadicStreamFunction/Wormhole.hs
taggingmonad/Control/Monad/SamplingMonad.hs
taggingmonad/Control/Monad/TaggingMonad.hs
taggingmonad/Data/Maybe/Util.hs
testing.hs
timetransform/TimeTransform.hs