Don't try to execute a Lua script.

* Move our site from our own Jinja2+Markdown to Pelican
* Move all pages from Markdown to RST(-highlightJS,+Pygmentize)
* Create plugin for documentation building (HTML for DocBook based and RST for hand-written texts)
  - Supports HTML for DocBook-generated documentation
  - Supports RST for HandWrittend Texts
  - Embedding into Pre-Based Templates
  - Using BeautifulSoup library for generating proper titles
* Adding Header to all site pages (e.g. Documentation)
* Modifications of CSS (we need to bring order to our CSS's)
* Modifications for DocBook xslt files and generations
* Add GitHub Ribbon
* Move FAQ to Documentation
* Documentation page is static now
* rocks.tarantool.org now in header

- change /etc/default format to Lua
- change defaults format to tarantool.cfg
- don't force logger/snap_dir/wal_dir/work_dir if it's set
- minor fixes in logging
- implement fio.dirname

Conflicts:
	src/lua/fiber.cc
	src/lua/msgpackffi.lua
	test/big/iterator.result
	test/big/lua.result
	test/box/msgpack.result
	third_party/lua-yaml/lyaml.cc

Conflicts:
	third_party/luajit

Implement functions which change their effective
user id ot the one of the definer during execution.

Conflicts:
	src/box/lua/box_net.lua