Clarified AsyncResoponse.resume(…) API docs.

- Added clarification on handling of unmapped exceptions.

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

- minor clarifications in keyStore(…) and trustStore(…) setters.

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