Merge pull request #23 from kevinwright/master

Renaming HListIso to Iso in the readme
Added type class for normalizing subtypes of a given type in an HList to that type.
Added test for Normalizer.
Avoid creating unexpected FilterAux instances.
Changed name of subtype unifier type class.
Merge pull request #24 from travisbrown/master

New subtype unifier type class
Updated.
Choose crossVersion style based on isSnapshot (thanks to Nikolas Evangelopoulos).
Minor spelling corrections in documentation.
Added example using subtype unifier type class.
Merge pull request #25 from travisbrown/master

Spelling and a new example
Added .jvmopts for sbt-extras.
Bumped plugin versions.
Added HKernel.
Merge remote-tracking branch 'github/master'
Revert "Bumped plugin versions."

This reverts commit 827d8ee0a32ec54e3cfbdc07b8b58211aa2a8790.
Bumped sbt-pgp version to 0.8.
Build for Scala 2.10.1; only use CrossVersion.full for Scala snapshots.
Sealing HNil trait eliminates non-exhaustiveness warning.
Eliminate deprecation warning.