Applied the Sangoma patch to FS version 1.2 in order to port to FS v1.6+

Sourced from:
http://gitlab.sangoma.com/projects/CORE/repos/freetdm/browse/public_freeswitch/sangoma-FS-1.2.patch

src/include/switch_apr.h

@@ -1103,6 +1103,12 @@ SWITCH_DECLARE(switch_status_t) switch_socket_accept(switch_socket_t ** new_sock
  */
 SWITCH_DECLARE(switch_status_t) switch_socket_connect(switch_socket_t *sock, switch_sockaddr_t *sa);
 
+/**
+ * Get socket fd for the switch socket passed
+ * @param sock The socket we wish to have fd
+ */
+SWITCH_DECLARE(int) switch_socket_fd_get(switch_socket_t *sock);
+
 SWITCH_DECLARE(uint16_t) switch_sockaddr_get_port(switch_sockaddr_t *sa);
 SWITCH_DECLARE(const char *) switch_get_addr(char *buf, switch_size_t len, switch_sockaddr_t *in);
 SWITCH_DECLARE(switch_status_t) switch_getnameinfo(char **hostname, switch_sockaddr_t *sa, int32_t flags);

src/include/switch_core.h

@@ -2652,6 +2652,19 @@ SWITCH_DECLARE(switch_status_t) switch_core_del_registration(const char *user, c
 */
 SWITCH_DECLARE(switch_status_t) switch_core_expire_registration(int force);
 
+/*!
+ \brief Get RTP port range start value
+ \param[in] void
+ \param[out] RTP port range start value
+*/
+SWITCH_DECLARE(uint16_t) switch_core_get_rtp_port_range_start_port(void);
+
+/*!
+ \brief Get RTP port range end value
+ \param[in] void
+ \param[out] RTP port range end value
+*/
+SWITCH_DECLARE(uint16_t) switch_core_get_rtp_port_range_end_port(void);
 
 SWITCH_DECLARE(char *) switch_say_file_handle_get_variable(switch_say_file_handle_t *sh, const char *var);
 SWITCH_DECLARE(char *) switch_say_file_handle_get_path(switch_say_file_handle_t *sh);

src/include/switch_types.h

@@ -1049,6 +1049,7 @@ typedef enum {
 	SWITCH_MESSAGE_INDICATE_UNBRIDGE,
 	SWITCH_MESSAGE_INDICATE_TRANSFER,
 	SWITCH_MESSAGE_INDICATE_RINGING,
+	SWITCH_MESSAGE_INDICATE_ALERTING,
 	SWITCH_MESSAGE_INDICATE_MEDIA,
 	SWITCH_MESSAGE_INDICATE_3P_MEDIA,
 	SWITCH_MESSAGE_INDICATE_NOMEDIA,