[krbdev.mit.edu #2536] Krb5 Admin Guide fails to document krb524

["Jeffrey Altman [Kermit Project]" via RT]

krb524 is not well documented in the Admin Guide. 

The use of _krb524._udp.<REALM> SRV records in DNS need to be added

The use of the "krb524_server"=<hostname>[:<port>]  value in the 
krb5.conf <REALM> ={}
needs to be documented.

The fact that the default port of 4444 is now being blocked by ISP's and 
therefore
an alternate port should be used needs to be added.

The algorithm for finding the default location of the krb524 service 
when no
other information is provided should also be specified.