For apps which depend on next() for bubbling errors to the top, allow
`swagger.errorHandler = "next"`
Added in headerParam function shortcut

Added in headerParam function shortcut to allow for expected behavior
between headerParams and all other param objects.
Merge pull request #88 from lefnire/next-error

For apps which depend on next() for bubbling errors to the top, allow `swagger.errorHandler = "next"`
Merge pull request #91 from DServy/master

Added in headerParam function shortcut
updated version
adding cors functionality to sample app