Set Vary header when doing content negotiation based on the Accept header (#1105)
Report errors with keystores

Code for loading the keyStore can throw an exception, which was
silently ignored.  By moving it inside an existing try-catch block, the
exception is reported in the log.

Also added an integration test.
Merge pull request #1236 from bwbecker/master

Using an invalid certificate keyStore should be (at least) reported in the log rather than failing silently.
Merge pull request #1232 from julienrf/fix/1105

Set Vary header when doing content negotiation based on the Accept header (#1105)