xen: fixed link order in generated Makefile

libm has to come last because other libraries might depend on maths
functions, not just main.o. Moved libocaml and libxencaml to the end
for the same reason (they certainly won't depend on any of the
project-specific C libraries).

This uncovered some "multiple definition" errors because mirage-xen
overrides the functions in bigarray and shared_memory_ring_stubs, but
was also listing them as libraries. These libraries are now removed
from the linker command.
When net_tap driver can't initialize, emit human error

Introduces mirage.runtime library and corresponding Mirage_runtime module.
Fixes #164.
oasis regen
Merge branch 'link-order' of git://github.com/talex5/mirage

Conflicts:
	CHANGES
bump working version to 2.0.2
Make Lwt.tracing instructions work for Fish shell too
Add a specific MacOS X platform

This lets us add MacOS X-specific libraries for the platform where
it diverges from stock Unix.  The first such use is in the networking
layer, where MacOS X provides the `vmnet` framework.

This patch defaults the `mirage CLI` to use the `MacOSX` mode on
that platform, and adds a `--no-macosx` override to force use of
the Unix mode (for advanced users).

The end-user capability added by this patch is that userlevel bridged
networking is possible using `vmnet`, and does not require any
third-party kernel modules to be installed either.

Requires ocaml/opam-repository#3135 to have the new packages
Bump to 2.0.2
improve the Mirage_runtime ocamldoc
Merge branch 'master' of github.com:mirage/mirage into tap-human-error

Conflicts:
	CHANGES
	lib/META
	setup.ml
Remove debug output from the main library; spotted by @samoht
Revert incorrect hunk merged as part of b97ceb19d6be0d474bd4305de9b33e87391cd6eb
Merge pull request #329 from avsm/osx-bridging

Add a specific MacOS X platform
Merge pull request #328 from talex5/fish

Make Lwt.tracing instructions work for Fish shell too
Merge remote-tracking branch 'upstream/master' into tap-human-error
sync CHANGES
Merge pull request #330 from avsm/tap-human-error

Update to #327: Tap human error
Merge remote-tracking branch 'upstream/master'

Conflicts:
	CHANGES
	_oasis
	lib/META
	setup.ml
IPV6: Add `MacOSX case to `configure`