This fix was okayed on jabber. It solves the problem in elapsed time
calculation between two DHCP packets. If the timestamp for both packets
is equal, the elapsed time is now 0. Previously, an exception was thrown.

The DNSClient uses timeout specified in ms. The documentation was wrong
saying that the timeout is specified in seconds.

merge in origin/trac2945 for some doxygen fixes

Conflicts:
	src/lib/dhcp/iface_mgr.cc

fix merge conflicts

This is for ticket 2945.
Don't use grep -q (not portable).
Also use quotes around "$werror_ok" just in test just in case is unset.

No changelog message as it appears it worked before but was just noisy.

Conflicts:
	src/bin/dhcp4/dhcp4_srv.cc
	src/bin/dhcp4/tests/dhcp4_test_utils.h
	src/bin/dhcp6/dhcp6_srv.cc
	src/lib/dhcp/pkt4.cc
	src/lib/dhcp/tests/pkt4_unittest.cc

 - Dhcpv{4,6}Srv::classifyPacket() is now better commented.
 - constants are now used instead of magic numbers
 - Pkt{4,6}::addClass is now better commented

Conflicts:
	src/lib/dhcp/iface_mgr.cc

On sluggish machines D2UpdateMgrTest.multiTransactionTimeout
failed intermittantly. A run-away test check was a bit too
stringent.

Adds support for DHCP-DDNS configuration parameters to b10-dhcp4.

Refactored some unit test classes in src/bin/d2/tests

Forgot to document params to doOneExchange.

Changed IP addresses used in tests in dhcp_parsers_unittest.cc
to comply test values recommened by RFCs.

Added missing test method commentary.

Conflicts:
	ChangeLog

Conflicts:
	src/lib/dhcp/iface_mgr.cc
	src/lib/dhcp/iface_mgr.h
	src/lib/dhcp/tests/iface_mgr_unittest.cc

Updated date in copyright header and reworded one message.