Merge remote-tracking branch 'origin/1.7' into 1.8

CMakeLists.txt

extra/dist/tarantool@.service.in

extra/exports

src/CMakeLists.txt

src/box/box.cc

src/box/engine.cc

src/box/engine.h

src/box/iproto_constants.c

src/box/iproto_constants.h

src/box/memtx_engine.cc

src/box/memtx_engine.h

src/box/vinyl.c

src/box/vinyl.h

src/box/vinyl_engine.cc

src/box/vinyl_engine.h

src/box/vinyl_space.cc

src/box/vy_log.c

src/box/vy_log.h

src/box/vy_mem.c

src/box/vy_mem.h