Update docs for Java 7 support. Made references more generic, with links to the release notes for version numbering. (Previous docs frequently referred to Java 6). Review in CR-1886.

git-svn-id: https://svn.forgerock.org/openam/trunk/openam@5638 0f4defcf-c51a-4c67-9f44-6fb5eba73c5d