https://bugs.launchpad.net/tarantool/+bug/1061147

Patch contributed by Mons Anderson

When accessing Lua stack via a numeric index, first calculate
absolute value of the index.

Make all subsystems (administrative console,
replication, memcached, binary protocol) use exception-based
socket API (sio.m).

Remove all fiber members related to socket I/O.
Remove fiber->peer and fiber->cookie.
The idea of the cookie is to preserve in the WAL
the originator of the request. This information is, however,
lost when saving a snapshot. To my knowledge there is no use
of this functionality, apart from pretty-printing
the WAL.

Peer is like cookie, but is textual and is used
for logging. However, now, as long as network errors
occur outside fiber context, most of the usefulness
is lost. The only remaining case is when someone is
trying to execute a write request on a read-only port.

For all other cases, sio.m already supplies SocketError
with peer name, and this is where it's most useful.

- Add support for [sS] format in box.pack (16-bit integers)
- Add support for [b] ans [s] format in box.unpack (8 and 16-bit integers)
- Fix docs

Check if the number is in the 32-bit range before converting
it to a 32-bit int, in box.pack('p'). If the number is large,
convert it to a 64-bit integer.

https://blueprints.launchpad.net/tarantool/+spec/support-bitwise-ops-in-lua

Make bitop available in the interpreter.
Extend the docs. Document tonumber64.

user can't make new snapshot until previous snapshot is saving

daemon can watch box.info.snapshotting variable do stop its loop temporary

A fix and a test case for Bug#0152018
"panic_on_wal_error doens't work for duplicate key errors"

Add a check for panic_if_error after invocation
of row handler, in addition to the log io cursor
checks.

fiber_setcancelstate(true) in admin fiber is no longer
necessary and can lead to bugs, if admin fiber works
with wal writer queue.

Move print_stat to admin.rl
Make tarantool_lua_stat.m a bit simpler.
Restore the original formatting of show stat.
Fix a bug when rps and total were reversed
in the new show stat output.

If there is an exception in a background (detached) fiber,
log it to the error log.

Provide a way to modify fiber name, so that created
background fibers can be distinguished by their name
(currently they all are called "lua").

Make sure we don't crash on NULL argument of error().

Fix coding style, add comments, remove
an unused variable (int raise).