---
-- Persistent table saving module

---
-- stores the couple key,data in a permanent data structure.
-- Permanent means not deleted after the end of the current session.
-- @param overwrite number one of session.OVERWRITE and session.FAILIFPRESENT
function session.save(key,data,overwrite)

---
-- return the string associated with key.
-- can be loaded with a loadstring(), remeber that returns "\a" if the 
-- requested session is locked
function session.load_lock(key)

---
-- removes saved info for key.
function session.remove(key)

---
-- removes lock for key.
function session.unlock(key)