@todo: manage instances in /etc/tarantool

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.

- write the docs
- remove unnecessary introduction of Perl
- properly implement, document and test box.fiber.wrap()
- rename box.find, explore alternatives (none)
- rewrite box.unpack('R') to reuse code and do
what's expected of it.

* Rewrite box.net.box:
	- connection process is in internal fiber, so
	  connector can reconnect lost connections
* Add box.fiber.wrap function that runs new detached fiber
* Add some tests

When server wrapper script failed to start
the server, it used to try to send a email
to somebody about this. This has never been
tested, nor used.

At least make sure it works when it does try
to do it.

twistd by default starts with umask 077.
This is why buildbot has umask setting.

rpm by default takes file and directory umask
from the build directory.

When building tarantool rpm under buildbot,
twistd default umask was inherited. Thus
all paths were created in rwx-- mode.

Now add to this cmake bug CMake bug 0012864.
That is, by default, cmake cpack generator
adds %dir directive for every intermediate
dir into the spec.

E.g. if there is a destination file /etc/rc.d/foo,
the spec gets
%dir /etc
%dir /etc/rc.d

Together with the default dir access mask of
twistd this nicely messed up our rpm install: an
install of Tarantool 1.4.8-59 rpm for CentOS would change
/etc and /usr access mode to 700.

Two things are done about that: Tarantool no longer
uses a cpack generated cpeck file. Extraneous %dir
directives are removed from the spec file. This
should minimize the damage of a broken twistd config,
should it happen again.

All buildslaves are reconfigured and restarted with umask 022.

(https://bugs.launchpad.net/tarantool/+bug/1050951)

(https://bugs.launchpad.net/tarantool/+bug/1032582)

Convert box.lua to box.lua.c and compile it in.
Fix broken out-of-source build of luajit, by adding
a few more generated files to touch-nocreate rule.

validation added.

modes are added.

* SIGUSR2 handler sends SIGHUP to logger
  (default extra/logger could already handle SIGHUP).
* Add some options to cmd-line (to override config's options).

scheme added.

line (if given) 2. current directory 3. INSTALL_PREFIX/etc/tarantool.cfg