feature(tarantool): implement hlua::{Push, LuaRead} for Tuple
requires !70 (merged)
changes:
- minor refactoring:
- Lua::execute -> Lua::eval + Lua::exec
- Tuple implementation tweaks (use NonNull instead of *mut, etc.)
- add support for box.NULL (when reading Option or can be read directly as hlua::Null)
- add False/True singleton type structs for convenience (useful when reading enums for dispatching on boolean values)
- add Typename struct which can be used to check the typename of the value on the stack
- add support for iterating of lua tables of lua tables
- add
tarantool::global_lua
function - add implementations of hlua::Push & hlua::LuaRead traits for tuple::Tuple
- other minor tweaks