Extract tests for application server from box/ to app/

test/app-tap/suite.ini

test/app/app.lua

test/app/cmdline.result

test/app/cmdline.test.lua

test/app/digest.result

test/app/digest.test.lua

test/app/fiber.result

test/app/fiber.test.lua

test/app/fio.result

test/app/fio.test.lua

test/app/ipc.result

test/app/ipc.test.lua

test/app/lua/fiber.lua

test/app/luafun.result

test/app/luafun.test.lua

test/app/pack.result

test/app/pack.test.lua

test/app/socket.result

test/app/socket.skipcond

test/app/socket.test.lua