Move packet.txt to the new directory doc/
Re-layout of the whole library.

Include files are moved to include/, source files are moves to src/

Build a static library, with pedantic and all warnings on debug mode.
Make it more portable, improve the code quality.
Add a quit reason for internal error.

Hope client are well designed to send those kind of reason :)
Keep size of dynamic fields, wich avoid useless allocations.

With this modification, user application can re-use structures and his
buffer.  It can be very useful for packet handling as an example, wich
will avoidallocation at each packet, and then possible failure.

Make sio_frombuf and sio_tobuf easily extendable.