Only expose public symbols

Adapted Makefile.in accidentally already came with previous commit:
	61e28884b2

src/SYMFILE

@@ -0,0 +1,86 @@
+getdns_strerror
+getdns_list_get_length
+getdns_list_get_data_type
+getdns_list_get_dict
+getdns_list_get_list
+getdns_list_get_bindata
+getdns_list_get_int
+getdns_dict_get_names
+getdns_dict_get_data_type
+getdns_dict_get_dict
+getdns_dict_get_list
+getdns_dict_get_bindata
+getdns_dict_get_int
+getdns_list_create
+getdns_list_create_with_context
+getdns_list_create_with_memory_functions
+getdns_list_create_with_extended_memory_functions
+getdns_list_destroy
+getdns_list_set_dict
+getdns_list_set_list
+getdns_list_set_bindata
+getdns_list_set_int
+getdns_dict_create
+getdns_dict_create_with_context
+getdns_dict_create_with_memory_functions
+getdns_dict_create_with_extended_memory_functions
+getdns_dict_destroy
+getdns_dict_set_dict
+getdns_dict_set_list
+getdns_dict_set_bindata
+getdns_dict_set_int
+getdns_dict_remove_name
+getdns_general
+getdns_address
+getdns_hostname
+getdns_service
+getdns_context_create
+getdns_context_create_with_memory_functions
+getdns_context_create_with_extended_memory_functions
+getdns_context_destroy
+getdns_cancel_callback
+getdns_general_sync
+getdns_address_sync
+getdns_hostname_sync
+getdns_service_sync
+getdns_convert_dns_name_to_fqdn
+getdns_convert_fqdn_to_dns_name
+getdns_convert_ulabel_to_alabel
+getdns_convert_alabel_to_ulabel
+getdns_validate_dnssec
+getdns_pretty_print_dict
+getdns_display_ip_address
+getdns_context_set_context_update_callback
+getdns_context_set_resolution_type
+getdns_context_set_namespaces
+getdns_context_set_dns_transport
+getdns_context_set_limit_outstanding_queries
+getdns_context_set_timeout
+getdns_context_set_follow_redirects
+getdns_context_set_dns_root_servers
+getdns_context_set_append_name
+getdns_context_set_suffix
+getdns_context_set_dnssec_trust_anchors
+getdns_context_set_dnssec_allowed_skew
+getdns_context_set_upstream_recursive_servers
+getdns_context_set_edns_maximum_udp_payload_size
+getdns_context_set_edns_extended_rcode
+getdns_context_set_edns_version
+getdns_context_set_edns_do_bit
+getdns_context_set_memory_functions
+getdns_context_set_extended_memory_functions
+getdns_context_get_api_information
+getdns_root_trust_anchor
+getdns_extension_set_libev_loop
+getdns_extension_set_libevent_base
+getdns_extension_set_libuv_loop
+getdns_context_set_return_dnssec_status
+getdns_dict_util_set_string
+getdns_dict_util_get_string
+getdns_context_get_num_pending_requests
+getdns_context_fd
+getdns_context_process_async
+getdns_context_set_use_threads
+getdns_extension_set_eventloop
+getdns_context_get_extension_data
+getdns_extension_detach_eventloop

src/mk-SYMFILE.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+cat getdns/getdns.h.in getdns/*.h | grep 'getdns_[0-9a-zA-Z_]*(' \
+| grep -v '^#' | sed -e 's/(.*$//g' -e 's/^.*getdns_/getdns_/g' > SYMFILE
+