Document how test_message_spec works
Add version_request/reply messaging protocol
Add a test for version_request in test_message_spec.py
Change version protocol according to the discussion in #2649
Remove version field from msg_header
Start protocol version from 4.0
Rewrite VersionReply spec using List and Unicode
Fix test failure in Python 2.6
Document version request messaging protocol
Document ipython_version bit more
Rename version_rep/req to kernel_info_rep/req
Rename remnant of version_request/reply protocol
Move protocol_version to core.release
Merge pull request #2649 from tkf/kernel-version

Add version_request/reply to message spec

and protocol_version added to core.release