async: remove old test
async: add OpenFlow_Header module

This module was reimplemented in three different places.
asyn: Add arbitrary instance and roudtrip test for Header
async: removed version-specific Header modules

These are now using OpenFlow_Header.
async: checkpoint implementation of async platform
async: xid type is now in OpenFlow_Header

Eventually, remove all aliases to this type.
async: added Message.header_of to 1.0 and 1.3
async: added Async_Platform.Message wrappers

Added wrappers for 1.0, 1.3, and uninterpreted chunks. This allows the platform
to be instantiated with any of these protocols.
.gitignore

vim swap files
:async Async_OpenFlow is the interface

Do not bother creating any other .mli files. Instead, expose all new modules as
submodules of Async_OpenFlow. This keeps the module namespace tidy.
async: added textutils as a dependency for travis
async: moved the Message signature out of Platform.

This signature is also useful when writing clients
async: fix compile errors in lwt
async: fix compile errors in lwt
Merge branch 'final-async' of github.com:frenetic-lang/ocaml-openflow into final-async
async: Async_OpenFlow.ClientServer

- This is a lower level interface than Async_OpenFlow.Platform.
- Serialization code has been factored out of Platform, since it
  is shared by both.
async: expose log
async: Chunk before OF1.0 and OF1.3 in signature
async: lots of optional logging in serializers
async: link with core and still run tests

See the comment at the end of test/Test.ml which explains the change.  Notice
that the test command in _oasis has also been updated.  I've changed
OpenFlow_Header to actully use core to demonstrate that make test doesn't hang.

@seliopou