Merge pull request #4 from oleksiyk/master

Reorganised errors, fully async API
Updated README and package.json for version 2.x
Updated JSON Schema Test Suite to latest, no errors to fix.
Added Grunt tasks for uglify and jshint.
JSHint fixes...
Merge pull request #5 from oleksiyk/master

Stack up errors for oneOf and anyOf validations as subErrors property
Updated .jshintrc and added mocha to Gruntfile
Fixed all JSHint errors
Renames...
Renames... #2
npm scripts...
Fixed JSHint errors in tests...
Updated README...