Merge remote-tracking branch 'origin/master' into tt-pythonize

include/errcode.h

src/box/alter.cc

src/box/box_lua.cc

src/box/box_lua_space.cc

src/box/index.h

src/box/key_def.cc

src/box/key_def.h

src/box/lua/schema.lua

src/box/schema.cc

src/box/schema.h

src/box/space.cc

src/box/space.h

src/box/tuple.cc

src/box/tuple.h

test/big/sql.result

test/big/tree_pk_multipart.result

test/box/alter_limits.result

test/box/alter_limits.test.lua

test/box/lua.result

test/box/lua.test.py