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

extra/dist/tarantoolctl.in

src/CMakeLists.txt

src/box/lua/net_box.lua

src/box/vinyl.c

src/lua/init.c

src/lua/pwd.lua

src/lua/string.lua

test-run

test/app-tap/pwd.result

test/app-tap/pwd.test.lua

test/app-tap/string.result

test/app-tap/string.test.lua

test/box/net.box.result

test/box/net.box.test.lua

test/parallel/call.result

test/parallel/call.test.py

test/parallel/parallel.lua

test/parallel/suite.ini