lldpd: trigger regular interface refresh when changing port ID

We don't want to call OS-specific methods. Let's just trigger a regular
interface refresh instead.
version: prepare a new release
debian: sync a bit with official packaging
osx: update version to 0.7.9
README: more about Cisco sending LLDP frames on VLAN 1
priv: don't output rc status twice when unable to open socket
lldpcli: add an option to enable promisc mode on managed interfaces

This allows LLDP frames to be received even when they are not in a
configured VLAN, like this may be the case with Cisco 2960.
lldpcli: give more details in the manual page about promiscuous mode
README: document the new promisc interface in README as well
frame: fix CDP checksum

The checksum of CDP frame is calculated off-by-one error when the length
of frame is odd, and the highest bit of the last octet is 1, which is as
a known question mentioned in wireshark.
cdp: don't expect and off-by-one checksum
lldpd: fix how LLDP can be disabled

Commit 46baf62775eaca47075e1d9966a2103fd466e4b3 broke the ability to
disable LLDP. Instead of trying to be smart, just enumerate all the
possible cases.
NEWS: add a word about ability to disable LLDP
lldpd: whitelist sendto, poll, recvmsg and readv in seccomp sandbox

With privilege separation and seccomp enabled, the monitor thread was
dying due to seccomp errors, while leaving the child alive. This whitelists
some extra syscalls to allow the monitor process to stay alive.
Merge pull request #70 from chutz/seccomp-whitelist

seccomp: whitelist sendto, poll, recvmsg and readv in seccomp sandbox
lldpd: fix use of NULL in execl*

See:
 http://c-faq.com/null/nullreq.html
NEWS: credit seccomp fix
lldpd: fix log_info

Currently none of the log_info msgs are getting
printed into syslog. vlog already does the right checks.
Remove the checks in log_info which is making all default log_info
prints no-ops

Also change severity of "interface reset timer" msg

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Sam Tannous <stannous@cumulusnetworks.com>
log: info messages should be logged on syslog but not on first debug level

Without `-d`, syslog should log info messages. With `-d`, they should
not be displayed. With `-dd`, they should be displayed. This is an
amendment of the previous patch.
Increase event buffer

This buffer is just used to drain the event socket

During high event traffic saw a no buffer space error. This and other
buffers need to be revisited.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Sam Tannous <stannous@cumulusnetworks.com>