* g_cnffile.c (krb__get_srvtabname): new function, looks up

	* g_cnffile.c (krb__get_srvtabname): new function, looks up
	[libdefaults]krb4_srvtab for use where KEYFILE used to be.
	* g_cnffile.c (krb__v5_get_file): new function, looks up argument
	in [libdefaults] and tries to open it as a filename. Returns
	filehandle (or NULL, if fopen failed.)
	(krb__get_cnffile, krb__get_realmsfile): use krb__v5_get_file to
	look up "krb4_config" or "krb4_realms" respectively. Also add
	$KRB_REALMS override for realms file.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@7096 dc483132-0cff-0310-8789-dd5450dbe970