Merge branch 'sophia-index'

CMakeLists.txt

src/CMakeLists.txt

src/box/CMakeLists.txt

src/box/alter.cc

src/box/box.cc

src/box/engine.cc

src/box/engine.h

src/box/engine_memtx.cc

src/box/engine_memtx.h

src/box/engine_sophia.cc

src/box/engine_sophia.h

src/box/index.cc

src/box/index.h

src/box/key_def.cc

src/box/key_def.h

src/box/lua/schema.lua

src/box/request.cc

src/box/schema.cc

src/box/sophia_index.cc

src/box/sophia_index.h