1) Moving ./test-run.py --gdb from xterm (or another standart X terminal emulator) to detached Screen session
2) Moving from unnecessary dependency "pexpect" to builtin "subprocess" module.

Move struct key_def into an own header.
Rename key_def methods to follow the coding style.
Rename field_data_type to field_type.
Instead of panicking on key_def initialization
error, throw an exception.

The allocator consists of a common slab cache, region and slab
allocators.
The patch provides unit tests.

It also modifies rlist_shift to be more in line with the
rest of rlist functions.

Derive some tests for multipart HASH indexes
from the original implementation by A. Demakov
before dropping the branch.

Don't drop entire vardir on test suite start, it may have
symlinks, configuration files, etc. - useful for debugging.

1) Temporary result files weren't deleted, if test's skipcond failed.
2) Vardir is removed when tests started.
3) Sort tests and test-suites by name
4) Added cleanup to box/lua.test

* memcached/expirations.test
* memcached/flush-all.test
* replication/memcached.test

Remove trailing spaces. Get rid of an unused method.

1. sleep(0.1) -> sleep(0.01)
2. _server -> serv, _replica -> _repl.

2. Refactor find_tests code
3. Rewrite and Add comment for chdir(base) (test_run.py:145)
4. Rewrite .gitignore file for new name of unit tests

- make the test suite actually paste
- remove the ugly copy-paste

- introduce primary_key_validate
- make asserts follow the coding style
- the original patch introduced a regression
in the error message when using a multi-part
key in update/delete: since, in the original patch,
key_validate was invoked before primary-key validation,
the error message changed to a less suitable one. Remove
this.
- an assert that something is not NULL is useless noise,
since a few lines down there's definitely going to be
NULL pointer dereference.

*Add uncommited file (lib/test-suite.py)

*Delete obsolete code

*Refactor of TestSuite and Test code

In the first place Tarantool has only one kind of test - functional testing.
But, when system began to grow, and each component (inside it) is needed to be tested thoroughly.

* 	Added support of UnitTest without creating of *.test file, that contains "run_test("*")"
	(Added UnitTest(Test) in the unittest_server.py, FuncTest(Test) in the tarantool_server.py.
	Now, when we search for tests we tell server to search them, and when we want to execute all
	tests TestSuite runs `execute` method of specific Test subclass)

* 	Fix of bug, that throwing OSError exception, when running by "python test-run.py",
	instead of "./test-run.py"

Rename tarantool_pthread.h to tt_pthread.h

This is a pre-requisite for addition of Perl stored procedures.