Added Invocation.Builder.accept(…) methods.

Signed-off-by: Marek Potociar <marek.potociar@oracle.com>
Updated examples to match recent Invocation.Builder API change.

Signed-off-by: Marek Potociar <marek.potociar@oracle.com>
Renamed ClientFactory to ClientBuilder.
Resolved JAX_RS_SPEC-335. 

- introduced Application.getProperties() method.

Signed-off-by: Marek Potociar <marek.potociar@oracle.com>
Resolved JAX_RS_SPEC-348.

- Added HttpHeaders.CONTENT_DISPOSITION and CONTENT_ID constants.

Signed-off-by: Marek Potociar <marek.potociar@oracle.com>
Fixed copyright header in HttpHeaders.

Signed-off-by: Marek Potociar <marek.potociar@oracle.com>