debian: Option to create patch ports through 'interfaces'

This is a port of commit d7aab661 ( rhel: Add Patch Port support to
initscripts.) from rhel to debian's ifupdown script.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
debian: Automatically start openvswitch before first invocation of ovs-vsctl.

In the 'interfaces' file, if an admin adds the openvswitch interface
in 'auto', ifupdown will try to create OVS interfaces even before
openvswitch has started. In a case like that, assume that the admin
knows what he is doing and try to start openvswitch.

The negatives I see are
1. /usr is NFS mounted, in which case expect the admin
to mount it through initramfs.
2. syslog through network may not be accessible.

This is similar to what rhel does with commit 602453000e28ec10
(rhel: Automatically start openvswitch service before bringing an ovs
interface up or down)

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
tests: Use the 'LARGE_MSECS' variation of time/warp at more places.

commit 8661af798(timeval: Provide a variation for time/warp command)
provided a variation of time/warp command to prevent multiple
invocations of time/warp. That commit changed only the users in bfd.at
and cfm.at as they used it the most. Since we haven't had any negative
confequences because of the change, add the remaining users.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>