fedora package: fix systemd ordering and deps.

There is a chicken and egg issue where common OVS
configuration uses a controller which is only accessible
via the network. So starting OVS before network.target
would break those configurations.

However, the network doesn't come up after boot because
OVS isn't started until after the network scripts tries
to configure the ovs.

This is partially fixed by commits:
   commit: 602453000e28ec1076c0482ce13c284765a84409
   rhel: Automatically start openvswitch service before bringing an ovs interfa

   commit: 3214851c31538e8690e31f95702f8927a8c0838b
   rhel: Add OVSREQUIRES to automatically bring up OpenFlow interface dependencies

But still there is the dependency issue between network.target
and openvswitch which this patch fixes it.  It provides two systemd
service units. One to run at any time (openvswitch-nonetwork.service)
which runs 'ovs-ctl start' and the other one (openvswith.service) to
run after network.target which works as a frontend to the admin.

The openvswitch-nonetwork.service is used internally by the
'ifup-ovs/ifdown-ovs' scripts when adding or removing ports to
the bridge or when the openvswitch.service is enabled by the admin.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
configure: Make autoconf fail if libtool is not installed.

Otherwise users get an error later like:
    ./configure: line 5093: syntax error near unexpected token
    `disable-shared' ./configure: line 5093: `LT_INIT(disable-shared)'
It's probably friendlier to make configuration fail earlier.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Update build requirements.

Libtool is now required as of commit 38b7a52b61 (openvswitch: Use libtool
and allow building shared libs).

It seems that a build requirement for Python slipped in a while back, for
generating ovs-vswitchd.conf.db.5, and no one complained, so we might as
well make it official.  (That will let us simplify some bits of the build,
too, since they won't have to be conditional on Python anymore, so I'm all
in favor of this change.)

Signed-off-by: Ben Pfaff <blp@nicira.com>