Add current status.

git-svn-id: https://svn.erp5.org/repos/neo/trunk@6 71dcc9de-d417-0410-9af5-da40c76e7ee4

README

 Nexedi Enterprise Objects
+
+  This implementation is based on the protocol version 2,
+  which is documented in doc/protocol.txt.
+
+  NEO must be rewritten based on the protocol version 3.0,
+  which is being documented in doc/spec.stx. The specification
+  is being worked on, and requires more effort to finish.