[master] rndc showzone / rndc delzone of non-added zones

[master] rndc showzone / rndc delzone of non-added zones

4030.	[func]		"rndc delzone" is now applicable to zones that were
			configured in named.conf, as well as zones that
			were added via "rndc addzone". (Note, however, that
			if named.conf is not also modified, the deleted zone
			will return when named is reloaded.) [RT #37887]

4029.	[func]		"rndc showzone" displays the current configuration
			of a specified zone. [RT #37887]