Prepare for multi-master.

 * Implement explicit API to create/start/stop/destroy remote clients
 * Merge re-connect loop && fiber code for JOIN and SUBSCRIBE
 * Re-use connection between JOIN and SUBSCRIBE
 * Split SUBSCRIBE code from pull_from_replica()
 * Improve logging and unify 'warning_said' logic
 * Fix fiber_cancel() on a replica fiber
 * Move the single instance of struct replica to cluster.h
 * Remove dependency on replica.h(cc) from recovery.h(cc)
 * Use enum replica_state for states instead of const char *

Change the logic of recovery_finalize() to open
the next xlog if the last xlog had zero rows.
Add a test case.

Remove recovery->finalize, use recovery->writer instead.

Fix a bug when the server would enter read-write mode prematurely
in hot standby mode, and let the script continue and try to create
spaces/indexes.

The bug is a regression introduced by the patch which changed cfg.listen
to a dynamic option.

This is an *incompatible* change: box.cfg{} used to return before binding
to the primary port, this is no llonger the case.

Always bind to the listen port in box.cfg{} call, not in the background,
and leave local hot standby mode *before* leaving box.cfg{}.

This avoids tons of tricky race conditions in user scripts when box.cfg{}
has ended but the server is actually still read only. Except, thanks to
another bug in box_set_cluster_id(), it wasn't really read-only, because
box_set_cluster_id() would switch off read-only mode before local hot
standby has ended (so a superposition of two bugs).

The manifestation of this  was as follows:

Imagine the following script:
    box.cfg{listen = 3301}
    box.schema.space.create('tester')
    box.space.tester:create_index('primary')

The server would start in local hot standby mode. Save a snapshot.
Fall through to DDL. Then leave local hot standby and turn on
WAL. The created space will end up not being in the write
ahead log.

The problem wasn't noticable in most cases, since the server could
bind to the primary port quite quickly.

Fix the test runner to detect a local hot standby server as started.

Add a workaround for gh-721 until a complete patch is ready.

Set xlog::vclock for write mode logs as well.
Move the check for matching signature into xlog_read_meta().
Convert xlog_open_stream() to use exceptions.

libcore is a thick a thick bundle with almost everything.
Rename it to libserver.

Extract the minimal server core with fibers & exceptions into libcore.

Add a prototype unit test for fibers.

This patch also changes box.info.server output for this case.

Avoid a name clash between variable name and struct name.

This patch adds a new implementation of UUID library.
New library generates RFC4122 compatible random-based (version 4)
UUIDs using data from /dev/(u)random. The uuidgen(2) syscall is also
supported on BSD system. `struct tt_uuid` redefined from RFC4122.
Complimentary functions rewrotten to remove dependecy on e2fs libuuid.
Lua bindings refactored to use new library and support all features.

Closes #317

 * remove vclock_merge
 * remove vclock_destroy
 * use `server` instead of `node`
 * use `signature` instead of `lsnsum`
 * refactor vclock_from_string code

node -> server
lsnmap -> vector clock
setlsn -> vclock

Make an explicit call to vclock for adding
a new server.

Word police: use server rather than "node".

* Remove a bogus message at the start of FindLibUUID.cmake.
* Move cluster_add_node to cluster.
* Extract UUID API into a (potentially) platform-independnent header
  tt_uuid.
* Add error codes for error messages used in UUID generation,
  triggers and consistency checks.
* Cleanup.

Introduce a structure to represent a thread with an event
loop in it.

Do not require a working event loop in say() or wal_opt_sync().

Move towards a uniform include scheme where header files are
stored along with the sources files, in the same directory.

We had to begin to use this scheme thanks to use of subprojects,
and a mix of two approaches turns the code base into a mess.

Rename tarantool_pthread.h to tt_pthread.h

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

Now that the network layer is exception aware, slowly
transit with the rest of Tarantool subsistems to
exception-based error handling model.

Make sure fiber_create() throws an exception
if there is insufficient memory for fiber or its
stack. Make the rest of the code aware of the change.

End the copyright madness. Tarantool authors maintain a shared
copyright on the code base. Remove individual copyright (c) from
specific files and put a single AUTHORS file in the project top.

Port tarantool to ObjectiveC.
Implement basic TNTException class and
 TNTFiberException and TNTBoxException subclasses.
Replace longjmp/setjmp with ObjectiveC exceptions.

mod/box: Restructurize request processing in the following way:

	try
		begin
		dispatch
		commit
	catch
		abort

where any error during request processing generate an exception.

Implement
https://blueprints.launchpad.net/tarantool/+spec/consistent-header-guards

Audit all header files in tarantool code base for consistent use
of header guards:
- consistent naming scheme, following doc/coding-style.txt
- header guard goes before the copyright
- each header is self-sufficient.
- add copyright headers where they were missing.

Remove __packed__, __unused__, __noinline__ and __regparm2__ from util.h,
since the name __unused__ conflicted with a parameter name in
third_party/valgrind/valrgind.h, which led to a dependency in inclusion
order between util.h and this header. The define names were not standard, I
couldn't come up with some meaningful and standard names, and they were only
saving some typing, while not providing any extra functionality.

Make a system specific check for MAP_ANONYMOUS
part of configuration process.
Follow up on a broken ENABLE_BACKTRACE switch
and fix a few cases which didn't compile with it.

Use CMake to:
- Compile tarantool_silverbox, tarantool_feeder.
- enable ./test-run testing out-of-source
- implement Debug/Release configurations
- add ENABLE_BACKTRACE ENABLE_TRACE and HAVE_BFD switches
- support auto-generated targets