Provide access to iproto sync via session.sync() binding.

The value is valid only at start of a Lua call before the first yield,
after which it may be replaced with a sync from another request
running on the same session.

Tarantool started to use getaddrinfo() to find suitable address for
binding both for IPROTO and CONSOLE ports. A hostname can be resolved to
various addresses families, depending on user settings. For example, all
moderns systems resolve 'localhost' to '::1' by default. This creates a
problem if one subsystem binds to '127.0.0.1' and some other tries to
connect '::1'. This patch unify hardcoded names and addresses in entire test
suite to use the same value. This is pre-requisite for #447, #368 and other
URI-related patches.

Other changes:

  * console.listen() now properly handles address arguments
  * console.listen() re-based on socket.tcp_server() code

Remove races in the test.
Re-enable the test after 'console' patch.

Also fix session.storage.test.lua (broken if called multiple times).

Make status() a method.
Update the docs.

Every fiber which may work with box needs to have a session,
since it's stores user id and the current transaction.

All bultin modules can be loaded with require('modulename')
instead of require('box.modulename')

Other changes:

 * _G.box is not initialized from tarantool_lua_init() anymore
 * box.info, box.stat, box.snapshot moved to src/box/lua
 * box.coredump() => coredump()
 * box.xxx = require('box.xxx') removed from tests

box.ipc         => require('box.ipc')
box.fiber       => require('box.fiber')
box.session     => require('box.session')
box.errno       => require('box.errno')
box.socket      => require('box.socket')
box.digest      => require('box.digest')
box.cjson       => require('box.json'), require('cjson')
yaml            => require('box.yaml'), require('yaml')
msgpack         => require('box.msgpack')
interactive     => require('box.interactive')

Closes #139

Add new system spaces _user and _priv to store users,
their passwords and their privileges.
Implement an authentication request in iproto protocol

Add a system space _func to store presistent information
about Lua functions. A function is now a subject
to ownership and privilege control.

Use MySQL-style sha1-double-hashing authentication by default.

Implement new Lua functions:

box.session.su()
box.session.uid()
box.schema.user.create()
box.schema.user.drop()
box.schema.user.grant()
box.schema.user.revoke()
box.schema.func.create()
box.schema.func.drop()

Store space creator in space definition.

What this patch doesn't implement:

- privilege checks in replication
- authentication of replication slaves
- exhaustive test coverage

This patch introduces backward-incompatible changes to select()
and adds couple new methods:

  * index:select(key) -> tuple, tuple, ... was changed to
    index:select(key, opts = {}) -> { tuple } where opts can be

       - iterator = ALL if key == nil or key == {} | EQ otherwse
       - offset = 0
       - limit = unlimited

  * index:get(key) -> tuple | nil | error on more than one tuple
    a wrapper for select() to get the single tuple

  * space:put(tuple) -> tuple
    an alias for space:replace() (to provide integrity with get())

Test suite, box.space and box.net.box API were also updated to
meet changes.

Change:
    box.space.name:insert() to box.space.name:insert{}
    box.space.name:replace() to box.space.name:replace{}
    box.space.name:delete() to box.space.name:delete{}
    box.space.name:auto_increment() to box.space.name:auto_increment{}
    box.space.name:select() to box.space.name:select{}
    box.space.name:update() now requires an explicit key and ops
    table.

Remove ellipsis from wrappers which don't strictly need it.
Remove backward-compatible next_equal/next/prev_equal/next/prev
iteration functions.
Cleanup hot_standby.test

Make index type optional when creating an index.

Use common context for lua reference and for trigger state.
Wrap all calls to lua_call into a try/catch block.
Introduce LuarefGuard
Remove box_luactx, it's not adding any value now.
Implement multiple triggers. Reuse code in lua/trigger.cc.
Misc cleanups.
Rename a few files.

on_replace triggers on struct lua_trigger.
Session and space triggers use the same technology.
Code cleanup.

This commit completely changes the data format used by Tarantool.
A new binary serialization format called MsgPack (http://msgpack.org)
has been introduced to store tuples, keys, request members, etc.
MsgPack supports various data types and hierarchical structures. Since
tuple & keys format has been changed, the binary protocol is no more
compatible with 1.5 clients.

The list of major changes:

 * Add MsgPack library and unit tests as a submodule
 * Add Lua bindings for the library and unit tests for it
 * Update IPROTO to use MsgPack for all kinds of requests
 * Change struct tuple to use MsgPack Array instead of BER-encoded fields
 * Remove fixed offsets from tuples (cannot be supported by MsgPack)
 * Replace const char *key, key_part pairs with MsgPack Arrays
 * Rework comparators and indicies to support MsgPack'ed fields
 * Merge NUM and NUM64 types into the one single type (NUM)
 * Rewrite box_lua.cc functions to support MsgPack instead of BER
 * Rewrite tuple_update to support MsgPack instead of BER
 * Totaly remove varint32 functions from all modules
 * Rework lua_tofield and YAML encoder to properly support Lua tables
 * Modifie bootstrap files and system spaces to use the new format
 * Add MsgPack support to the test system via msgpack-python
 * Update tests to use proper data types and remove unneeded box.packs

Tarantool 1.6 is the world's first MsgPack-based database!

Fix session and bad_trigger test
Fix output (remove garbage, fix whe interrupted by exceptions)
Add list of broken tests when tests are run with "./test-run.py --force" flag (make test-force)

Since connect/disconnect events in iproto run outside
fiber context, queue execution of on_connect/on_disconnect
triggers through the request queue. Generalize the request
queue for that purpose.

Implement a framework for on_connect/on_disconnect triggers
and Lua bindings for it.

Add tests and docs.