-fixed up AresDns::checkDnsChange to be able to compare IPv6 DNS servers instead of just V4 servers
-modified API used to retrieve DNS servers for Windows systems from GetNetworkParams to 
  GetAdapterAddresses (supported on Windows XP / Server 2003 and above)
 -will fallback to GetNetworkParams if unable to retrieve servers via GetAdapterAddresses (this 
  will happen on Windows 98 and Server 2000 machines)
 -GetNetworkParams issues: 
    -does not support IPv6
    -was exhibiting a MS bug that could cause 0 DNS servers to be returned if many 
     ares instances where init'd at the same time (ie: could happen when creating 
     many SipStack instances at the same time)
 -more efficient lookup when ARES_FLAG_TRY_NEXT_SERVER_ON_RCODE3 ares option is used - no need to 
  lookup the physical address of each DNS server separately 
 -cleanup fallback to local named for all platforms - now uses common code

git-svn-id: https://svn.resiprocate.org/rep/resiprocate/main@10675 ddefafc4-47db-0310-ae44-fa13212b10f2