Merge pull request #272 from atddio/master

Dockerfile to automatically build ghcjs
update TestRunner for new optparse-applicative
skip intermediate thunk for inline expressions
[Docker build] removed max-backjumps

With max-backjumps=-1 cabal can not resolve dependencies building
ghcjs and ghcjs-prim, without it it succeeds.

I don't understand cabal well enough to understand what this means,
though I am glad it is building.
Merge branch 'master' of https://github.com/ghcjs/ghcjs