libdns cleanup

Since we don't need backwards compatibility we can remove most multiplicated functions:

• dns_acl_match()
• dns_aclelement_match()
• dns_adb_createfind()
• dns_adb_probesize()
• dns_byaddr_createptrname()
• dns_cache_create()
• dns_client_createx()
• dns_db_dump()
• dns_db_load()
• dns_dispatch_addresponse()
• dns_dispatch_createtcp()
• dns_dispatch_gettcp()
• dns_dnssec_findmatchingkeys()
• dns_dnssec_findzonekeys()
• dns_dnssec_verify()
• dns_dt_create()
• dns_fwdtable_find()
• dns_iptable_addprefix()
• dns_keytable_add()
• dns_master_dump()
• dns_master_dumpinc()
• dns_master_dumptostream()
• dns_master_loadfile()
• dns_master_loadfileinc()
• dns_master_stylecreate()
• dns_message_logfmtpacket()
• dns_message_logpacket()
• dns_request_createraw()
• dns_request_createvia()
• dns_resolver_createfetch()
• dns_ssutable_checkrules()
• dns_ttl_totext()
• dns_view_find()
• dns_view_findzonecut()
• dns_view_flushcache()
• dns_view_setcache()
• dns_xfrin_create()
• dns_zone_dumptostream()
• dns_zone_forwardupdate()
• dns_zone_getoptions()
• dns_zone_getserial()
• dns_zone_notifyreceive()
• dns_zone_setfile()
• dns_zone_setoption()
• dns_zt_apply()
• dst_context_create()
• dst_key_generate()
• dst_lib_init()