Fast table serialization for Lua

require "marshal"

Provides:

  s = table.marshal(t)      - serializes a table to a byte stream
  t = table.unmarshal(s)    - deserializes a byte stream to a table
  t = table.clone(orig)     - deep clone a table

Features:

Serializes tables, which may contain cycles, Lua functions with upvalues and basic data types.

Limitations:

Coroutines are not serialized and nor are userdata, however support
for userdata the __persist metatable hook can be used.

The top level object must be a table. Metatables and function environments are not serialized.

Cross endianness is not supported.