Log Message:
Changes:
 o Zone file reading support added (Dnsruby::ZoneReader) 
 o Name and Label speed-ups 
 o CodeMapper speed-ups 
 o DHCID RR added 
 o LOC presentation format parsing fixed 
 o KX RR added 
 o Quotations now allowed in text representation for ISDN, X25 and HINFO 
 o AFSDB from_string fixes 
 o Fixing CERT types and from_string 
 o CERT now allows algorithm 0 
 o Fix for DS record comparison 
 o HIP RR added 
 o Minor bug fixes 
 o IPSECKEY RR added 
 o Clients can now manipulate Name::Labels