Update upper bounds for some dependencies

Two years is a long time, so bump upper versions for QuickCheck2,
test-framework and test-framework-quickcheck2 to the versions that I
can test now with. No code changes needed.
Add a lint Makefile target

Just using default rules, but easier than to run it by hand.
Fix hlint suggestion

Just one suggestion for now.
Small white-space alignment change
Bump up version and update homepage settings

As part of the move from code.google.com to github, update home page,
issue tracker, git repository, etc., and bump up version for a new
trivial release.
Fix small typo in docstring of ParseKMGT

Maybe not typo, but at least the explanation was unclear.
Further haddock updates

parseValue had an identical docstring to parseGeneric, even though the
signatures are quite different.
Small update to README.md

Explain a bit the rationale behind the 'bare-bones' approach
(vs. using TemplateHaskell and fancier things).