Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC 249766: Use a higher TTL (128) for DHCP packets.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Make dhclient use bootpc (68) as the source port for unicast DHCPREQUEST
packets instead of allowing the protocol stack to pick a random source port.

This fixes the behaviour where dhclient would never transition from RENEWING
to BOUND without going through REBINDING in networks which are paranoid about
DHCP spoofing, such as most mainstream cable-broadband ISP networks.

Reviewed by: brooks
Obtained from: OpenBSD (partly - I'm not convinced their solution can work)
MFC after: 1 week (pending re approval)

Add __FBSDID to all .c files in dhclient to aid in determining file
versions when dealing with user problems.

This commit was generated by cvs2svn to compensate for changes in r147072,
which included commits to RCS files with non-trunk default branches.

Import the OpenBSD dhclient as shipped with OpenBSD-3.7 (the tag
OPENBSD_3_7).