TODO

Data.ByteString.Lex.Integral:
    * See how many of the new specializations ({Int,Word}{8,16,32,64}) are actually useful in practice.
    * relax the Integral constraint to Num wherever possible?
    * Correct the performance regression in packDecimal/numDecimalDigits

./test/:
    * get the test suite to return error codes as appropriate; otherwise TravisCI will always say it works!

./bench/html/:
    * Update the css to match the changes elsewhere
    * set up benchmarking in Cabal

Data.ByteString.Lex.Lazy.*:
    * reintroduce modules for working with lazy bytestrings

README.md:
    * Add coveralls badge? Other stuff from <https://raw.githubusercontent.com/mtchavez/circleci/master/README.md>

.travis.yml:
    * Use hpc-coveralls: <http://guillaume-nargeot.github.io/haskell/2014/04/01/haskell-code-coverage-coveralls-support/>
        * also cf., <https://gist.github.com/VoQn/1470421>
    * Use hlint: <https://github.com/guillaume-nargeot/project-euler-haskell/blob/master/.travis.yml>
    * Figure out how to get Haddock's coverage info out as an exit code