LuaSocket get-/setoption methods

[Zash]

LuaSocket exposes an interface to getsockopt(2) and setsockopt(2), in the form of the :getoption() and :setoption() methods exposed on TCP sockets.
These are not available on LuaSec wrapped TLS sockets. I wish they were.

[Tieske]

same for getpeername

[Ensber]

and getsockname

[brunoos]

we can import more code from luasocket to offer get/set options, but luasec is based on the version 3.0-RC1 of luasocket, which has less options than the current version.