Marshall replication using the primary port.

Split iproto requests into two categories: DML and admin.  Change
PING request code to 64, to lay within admin request range.
Perform administrative requests synchronously, without pushing
them into an event queue.
Add a new administrative request, IPROTO_SUBSCRIBE.

Use dynamic memory for struct iproto_request. Introduce memory
management.

Remove replication_port from the configuration file and
update tests.

Fix the test runner so that it correctly generates
replication_source to point to the primary port.
Add variable arguments to IllegalParams.
Move replia-related recovery methods to a new header, replica.h.

Remove a debug printout from box.net.lua

Update tests.

'print_log'`

Conflicts:
	src/box/lua/box_net.lua
	test/box/ipc.test
	test/box/net.box.result

 + memory leak in box.net.box (timeouted responses)
 + remote:ping() never throw exception

Conflicts:
	doc/user/target.db
	src/ipc.cc
	test/box/ipc.test

Conflicts:
	doc/user/stored-procedures.xml

Conflicts:
	src/box/CMakeLists.txt

Conflicts:
	src/lua/init.cc
	test/box/fiber.result
	test/box/fiber.test
	test/module/net_sql.mysql.result
	test/module/net_sql.mysql.test

Closes #161

Conflicts:
	.gitmodules
	CMakeLists.txt
	extra/rpm.spec.in
	src/CMakeLists.txt
	src/box/box.cc
	src/box/box.h
	src/log_io.cc
	src/recovery.cc
	src/tarantool.cc
	test/unit/CMakeLists.txt
	test/unit/test.c

Fix styler
Clarify tricky pieces of the code (at least make them clearer to yours
truly).
Fix a bug with incorrect return value from fwrite() & O_DIRECT.