slua v1.5.1 Release

upgrade lua vm to luajit-2.0-beta3
add luafunction.cast function to cast lua function to delegate
add support to create multi state, see multistate demo
add support for simulator for iOS
add support to export interface
auto generate bytecode for all platform
add lua console to run lua code on-fly
add byte array to handle byte[] data instead of lua string
add byteshelper to optimize gc alloc on write data to byte array
integrate luasocket(minimize) to support tcp debugger
dump stack when error report in Editor
fix out/ref parameter of delegate
some fix for unity 5.6x
some fix for unity 4.x
fix null reference in il2cpp
much minor fix