JERSEY-1867: documentation "security" chapter.

- PS2: rebased + latest version of jersey.ent used.
- PS3: review comments incorporated.

Change-Id: I351e4a8aa1d73aee80ed2a01c67257ca92cf59d9
Signed-off-by: Marek Potociar <marek.potociar@oracle.com>
Merge "JERSEY-1867: documentation "security" chapter."