Adding content-disposition header for files
Merge branch 'develop' of git://github.com/walmartlabs/hapi into develop

Merging upstream
Cleaning up content-disposition test
Adding another content-disposition related test
Response validation now has sample and onInvalid settings
Fixing response validation tests
Cleaning up response validation sampling
Merge pull request #340 from wpreul/develop

Content-disposition header + Response validation settings