Raise exception Bad_option for unparseable or invalid options.
Changes per @avsm feedback, w/exception of catching `Failure`
Add try block for get_uint16 failure in MSS checks; separate check_mss to own function.
Wrap variable-length option parsing in a `try` per @avsm's advice.
Quieten down the stack logging rate by not announcing IPv6 packet discards
bump to 1.1.6
Merge pull request #58 from avsm/master

quieten logging from tcp when handling ipv6
s/Failure/Invalid_argument/g
Do not expose the `Tcpip_checksum` module twice in the `oasis`

Lift it up to the toplevel `Tcpip` library, since it's just external
function declaration and no other values.
Merge pull request #60 from avsm/fix-checksum-modules

Do not expose the `Tcpip_checksum` module twice in the `oasis`
Merge branch 'fix-tcp-unmarshalling' of git://github.com/yomimono/mirage-tcpip into yomimono-fix-tcp-unmarshalling
Add `opam` file to permit easier local pinning, and fix Travis to use this.
Merge pull request #61 from avsm/master

Release 1.1.6
Added checksum_stubs.c from mirage-platform

This is only used for networking, and isn't specific to a Mirage
platform (the Xen and Unix versions should be the same).

We now always use the x86_64-specific optimised version from mirage-xen
on x86_64 (whether Unix or Xen), and always use the generic version from
mirage-unix on other platforms.
Merge pull request #63 from talex5/checksum

Add checksum_stubs.c from mirage-platform
Avoid namespace clash with local ntohs/htons functions.

These are macros in MacOS X, which causes a clash when compiling
our local copies.  Instead of a local undef hack, this just explicitly
renames the local functions to indicate that we want to use this code
rather than the system equivalents (this improves reproducibility
across different architectures and development operating systems)

This fixes the build on MacOS X.
Travis: also build the Mirage/Xen backend of the website
travis: build properly
Turn TCPv4 into a real FLOW-compatible interface.

Needs the associated changes in Mirage_types
Merge pull request #64 from avsm/fix-macos-build

Avoid namespace clash with local ntohs/htons functions.