Merge branch '1.6' of https://github.com/tarantool/tarantool

extra/schema_erase.lua

extra/schema_fill.lua

src/box/CMakeLists.txt

src/box/bootstrap.snap

src/box/lua/init.c

src/box/lua/upgrade.lua

src/box/tuple.h

src/coeio.c

src/lib/small

src/lua/console.c

src/lua/console.lua

src/lua/tap.lua

test/box-py/bootstrap.result

test/box-py/bootstrap.test.py

test/box/access_misc.result

test/xlog/suite.cfg

test/xlog/suite.ini

test/xlog/upgrade.lua

test/xlog/upgrade.result

test/xlog/upgrade.test.lua