Avoid an unnecessary interlocked instruction or pipe write
in fiber_wakeup(), it's always called from the same cord
as the one to which the event loop belongs.

Use ev_feed_event() with EV_CUSTOM instead.

Rename Factory to Engine, Factory was a name we couldn't swallow.

Introduce Handler class to disambiguate Engine from Space
(hello, MySQL).

Remove the branch which saves a snapshot without a fork.

Build Sophia before trying to link with it.

Conflicts:
	src/box/memtx_hash.cc
	test/unit/CMakeLists.txt

Conflicts:
	test/box/box.net.box.result