fix #277 aria.core.JsonValidator.normalize throws an object

aria.core.JsonValidator.nomalize when failing throws an object, now it throws an instance of Error.

Close #583
feat #584 bump attester to 1.2.0

Close #584.
refactor Update Syn

Close #33 close #491
fix #558 test on utils.Dom fails in Chrome

In Chrome and Safari the test test.aria.utils.Dom fails in attester because the body of the iframe content doesn't have an height and doesn't scroll properly

Close #581
refactor Stricter options on JsHint

Enable more strict option on JsHint and update the package dependencies.

Close #244 close #579

Conflicts:
	package.json