Add session type; (s,g)etsession to ssl objects
session: Add `asn1` method
session: prevent double frees on manual __gc invocation
context: Add setsessionidcontext and setsessioncachemode
ssl: Add method `reused` which returns if a session has been regotiated or not
ssl.lua: Add config options to initialise setsessioncachemode and setsessionidcontext
context: Use a seperate method table
Add sample of session reuse