also added some more hack to the DB unittests so add/delete zone tests
can work with mock accessor, too.

Conflicts:
	src/lib/dhcpsrv/cfgmgr.cc
	src/lib/dhcpsrv/cfgmgr.h

The updated description specifies that the change was in the DHCP code.
Also, the updated entry points out that new code is used internally by
the DHCP server. Okayed on jabber.

Conflicts:
	src/bin/dhcp4/config_parser.cc
	src/bin/dhcp6/config_parser.cc

Conflicts:
	src/lib/dhcpsrv/Makefile.am

it's probably more intuitive than False.

Addendum to ticket 2524 - the makefile omitted to make sure the
dhcpsrv_messages.mes file were in the distribution tarball

Using g++, on some systems a call to system() is tagged with the
"warn unused result" attribute.  As all warnings are promoted to
errors, all uses of system() must use the returned status code.

I thought that explicit type name made the code more readable, but maybe
that's not the case so I've removed it now.

It still needs to be specified in the other constructor.