change validation.fail.toOption to use a fold for compatibility with scalaz7
git rid of some unneeded imports of scalaz
Merge pull request #244 from stew/52be281ef0c64cd72883e05def784eeab3ad0858

change validation.fail.toOption to use a fold for compatibility with scalaz7
Merge pull request #245 from stew/scalaz7

git rid of some unneeded imports of scalaz
Upgrade json4s to 3.1.0.
Update Scalate to 1.6.1.

Scalate 1.6.0 was accidentally published against Java 7.  We want to
maintain Java 6 compatibility.
Merge branch '2.2.x' into develop