Romlib makefile refactoring and script rewriting ...

The features of the previously existing gentbl, genvar and genwrappers
scripts were reimplemented in the romlib_generator.py Python script.
This resulted in more readable and maintainable code and the script
introduces additional features that help dependency handling in
makefiles. The assembly templates were separated from the script logic
and were collected in the 'templates' directory.

The targets and their dependencies were reorganized in the makefile and
the dependency handling of included index files is possible now.
Incremental build is available in case of modifying the index files.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I79f65fab9dc5c70d1f6fc8f57b2a3009bf842dc5

doc: Reorganise images and update links ...

Change-Id: I679d1499376a524bef1cfc33df995b0a719b5ac8
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

doc: Set correct syntax highlighting style ...

Several code blocks do not specify a language for syntax
highlighting. This results in Sphinx using a default highlighter
which is Python.

This patch adds the correct language to each code block that doesn't
already specify it.

Change-Id: Icce1949aabfdc11a334a42d49edf55fa673cddc3
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

doc: Remove per-page contents lists ...

These are no longer needed as there will always be a table of contents
rendered to the left of every page.

Some of these lists can be quite long and, when opening a page, the
reader sees nothing but a huge list of contents! After this patch,
the document contents are front-and-centre and the contents are
nicely rendered in the sidebar without duplication.

Change-Id: I444754d548ec91d00f2b04e861de8dde8856aa62
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

doc: Normalise section numbering and headings ...

Required work to make all documents sit at the correct levels within
the document tree and any derived content like the table of contents
and the categories in the sidebar.

Change-Id: I4885fbe30864a87c8822ee67482b71fb46a8fbc6
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

doc: Move documents into subdirectories ...

This change creates the following directories under docs/
in order to provide a grouping for the content:

- components
- design
- getting_started
- perf
- process

In each of these directories an index.rst file is created
and this serves as an index / landing page for each of the
groups when the pages are compiled. Proper layout of the
top-level table of contents relies on this directory/index
structure.

Without this patch it is possible to build the documents
correctly with Sphinx but the output looks messy because
there is no overall hierarchy.

Change-Id: I3c9f4443ec98571a56a6edf775f2c8d74d7f429f
Signed-off-by: Paul Beesley <paul.beesley@arm.com>