doc/{branch}/... -> doc/...
Master/Stable -> One-page/Multi-page

    1. Unified blurb for every site page
    2. remove tnt-html.xsl.cmake tnt-html-chunk.xsl.cmake in favor of
    --stringparam and -param flags of xsltproc and saxon
    3. Create flags for input/output in static.py script for OOS build

All layouts are in doc/www-data.in/_layout and are written in Jinja1
(django-like templates). All texts are in doc/www-data.in/_texts

Text files contains YAML files with chunks of markdown strings:
```
$module:
    $uno: |
        some text in markdown
    $dos: |
        it may be multiline
    $tres: |
        # header 1
        ```
        may have some embedded code
        ```
        e.t.c
    ...
```
where `$module` is name of layout file, `$uno`, `$dos`, `$tres`... are
name of parts (template parts `{{ $module.$part }}`)
Site still stores files in `doc/www-data` for copying on server.
Also it integrates documentation (only on stable/master branches) into site (still templlates)
Usage of new `extra/static.py`:
```bash
$ cmake . -DENABLE-DOC=TRUE
$ make
$ cd /doc/www-data.in/
$ ../../extra/static.py site `# build site`
$ ../../extra/static.py docs `# embed docs`
```

 ### documentation building

Add `html-saxon-chunk` and `html-chunk` targets for building chunked
html documentation.

`make` in `doc/user` now builds `html-saxon` and `html-saxon-chunk`
targets

Make w3c isopub.ent entity files available locally,
since it is part of nobody-knows which package on Ubuntu,
and may be missing completely on other distributions.

On Ubuntu 13 even though it is part of mathml, it's not listed
properly in /etc/xml/catalog apparently.

This fixes xsltproc warnings and speeds up manual generation
significantly.

The patch which removes the CPack-generated spec
and adds a proper spec for client, server and library
was done by Dmitry Simonenko.

Hand-port the patch to the master, since it's gone too
far away from the origin and merging it ends up in a mess.

Document bind_ipaddr (lp:bug#1032240).
Separate triggers into an own section.
Clarify that the network now is fully asynchronous.
Clarify how atomicity works in stored procedures.
Provide an overview of possible operations in the data model.
Add a stub for system-specific installation notes.
Fix all references to be stable between builds of the
manual, so that an external link to, say, memcached-protocol
stays valid over time.

Apply documentation edits suggested by Peter Gulutzan.
Fix 'relink' target to correctlly build target.db.

https://bugs.launchpad.net/tarantool/+bug/837484

- add content
- speed up rebuild by keeping static stuff in www-data
- change the layout and stylesheet

Add more content to the user guide (language reference, memcached support).

Explain how to configure a namespace.
Tweak some error messages on the way.