[AME-2371]Update endpoint chapter, based on additions per AME-2158 to protect users, groups, agents REST APIs with authn/authz filters.

git-svn-id: https://svn.forgerock.org/openam/trunk/openam@6348 0f4defcf-c51a-4c67-9f44-6fb5eba73c5d
Updated fix for OPENAM-2817 to add correct XML header.

git-svn-id: https://svn.forgerock.org/openam/trunk/openam@6349 0f4defcf-c51a-4c67-9f44-6fb5eba73c5d