Update about.rst (apache#129)

4.13.1.0 documentation release update (apache#104)

* Update changes.rst

* what's-new-in-4.13.1.0-about-page

* Update upgrade-4.13.rst

* Update api-changes.rst

add note on firewall for integration.api.port 8096

Signed-off-by: Rohit Yadav <[email protected]>

Updated documentation for 4.12.0.0 release