Add documentation of the xlat tables library V2 ...

The documentation describes the design of the translation tables
library version 2 used by the ARM Trusted Firmware.

The diagram file has been created with Dia version 0.97.2. This tool
can be obtained from: https://wiki.gnome.org/Apps/Dia/Download

Inkscape has been used to generate the *.png file from the *.dia file
to work around a bug in the generation of *.png files in some versions
of Dia.

Change-Id: Ie67d9998d4ae881b2c060200a318ad3ac2fa5e91
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

Manual fixes to reST documentations ...

Non-automated fixes to the converted documentation.

Change-Id: I61f3d37c7a8d6a56a7351048060b970c5b3751e4
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

Convert documentation to reStructuredText ...

Due to recent issues in the rendering of the documentation on GitHub and
some long-standing issues like the lack of automatic table of content in
Markdown, the documentation has been converted to reStructuredText.
Basic constructs looks pretty similar to Markdown.

Automatically convert GitHub markdown documentation to reStructuredText
using pandoc.

Change-Id: If20b695acedc6d1b49c8d9fb64efd6b6ba23f4a9
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>