Doc: Updated for Version 1.0-RC2

This patch updates the documentation landing
page (readme.rst) to reflect the latest
release (Version 1.0-RC2).

* Updated Sphynx documentation version tags
* Updated Doxygen documentation version tags
* Updated features/capabilities described in readme.rst

Change-Id: Ic01b235cf3276d9d0aee6406ca9b57982001c7f0
Signed-off-by: Tamas Ban <tamas.ban@arm.com>