2930. [experimental] New "rndc addzone" and "rndc delzone" commads

2930.	[experimental]	New "rndc addzone" and "rndc delzone" commads
			allow dynamic addition and deletion of zones.
			To enable this feature, specify a "new-zone-file"
			option at the view or options level in named.conf.
			Zone configuration information for the new zones
			will be written into that file.  To make the new
			zones persist after a restart, "include" the file
			into named.conf in the appropriate view.  (Note:
			This feature is not yet documented, and its syntax
			is expected to change.) [RT #19447]