Added configurable status and statusText fields

- schema.options can now contain status and statusText
- if present, the respective values are sent back to the client in case of validation errors
- if not, default is 400 (status) and "Bad Request" (statusText)
Fixed mocha complaint about global leaks

- added var keyword to options so that mocha does not complain about global leaks
Merge pull request #3 from rbarbey/master

Added configurable status and statusText fields