A variety of changes.

* support -XDataKinds, -XExplicitNamespaces
* passing tests for that
* failing exactprint tests for whitespace, unpack pagmas

Sorry about being merged together. It was already too much work to get the changes I recorded in http://code.haskell.org/~aavogt/add-failing-test-for-_xexplicitnamespaces.dpatch into git.