* configure.in: Enable internal WITH_BRIDGE support not just for LXC or
QEMU, but also for --with-network.  Russell Haering reported that
compilation failed when configured with --without-lxc --without-qemu.
Details: http://thread.gmane.org/gmane.comp.emulators.libvirt/11928
* src/bridge.h: Use #if WITH_BRIDGE, rather than currently-equivalent
"#if defined(WITH_QEMU) || defined(WITH_LXC)"

IFF_VNET_HDR is a tun/tap flag that allows you to send and receive
large (i.e. GSO) packets and packets with partial checksums. Setting
the flag means that every packet is proceeded by the same header which
virtio uses to communicate GSO/csum metadata.

By enabling this flag on the tap fds we create, we greatly increase
the achievable throughput with virtio_net.

However, we need to be careful to only set the flag when a) QEMU has
support for this ABI and b) the value of the flag is queryable using
the TUNGETIFF ioctl.

It's nearly five months since kvm-74 - the first KVM release with this
feature - was released. Up until now, we've not added libvirt support
because there is no clean way to detect support for this in QEMU at
runtime. A brief attempt to add a "info capabilities" monitor command
to QEMU floundered. Perfect is the enemy of good enough. Probing the
KVM version will suffice for now.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>

Done with these commands:
git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* vim:(.|\n)*,\n,'

git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* Local variables:\n(.|\n)*,\n,'

Use <config.h>, not "config.h", per autoconf documentation.
* Makefile.cfg (local-checks-to-skip) [sc_require_config_h]: Enable.
* .x-sc_require_config_h: New file, to list exempted files.
* Makefile.am (EXTRA_DIST): Add .x-sc_require_config_h.

	* src/bridge.c, src/bridge.h, src/qemu_conf.c, src/qemu_conf.h,
	  src/qemu_driver.c, src/qemu_driver.h, src/test.c: Disable more
	  of qemu if configured --without-qemu.

  stylesheet
* docs/*: regenerated
* src/bridge.c src/bridge.h src/buf.c src/iptables.c src/libvirt.c
  src/qemu_driver.c src/qemu_driver.h src/uuid.c src/uuid.h: cleanup,
  addd comments, made functions static and fixe a few bugs
Daniel

        * configure.in: add --disable-bridge-params, check
        for libsysfs and various kernel headers

        * bridge.[ch]: add code for managing bridges

        * qemud/Makefile.am: add bridge.[ch] and link against
        libsysfs if enabled.

        * qemud/conf.c: add support for bridge config.

        * qemud/internal.h: add various bridging bits

        * qemud/qemud.c: implement qemudStartNetworkDaemon()
        and qemudShutdownNetworkDaemon().