BUG#20456137: DUPLICATED CODE ON SQL/RPL_GROUP_REPLICATION.H

sql/rpl_group_replication.h contains duplicated functions signatures
already defined on include/mysql/group_replication_priv.h
There is no need for that since:
 1) server files can access the functions through the regular
    include files;
 2) plugins have access through
    include/mysql/group_replication_priv.h

To solve the above duplication of code, the unneeded functions
signatures are removed from sql/rpl_group_replication.h

Author: nacarvalho

sql/rpl_group_replication.cc

@@ -221,7 +221,8 @@ uint get_group_replication_members_number_info()
 
 
 /*
-  Server access methods
+  Server methods exported to plugin through
+  include/mysql/group_replication_priv.h
 */
 
 bool is_server_engine_ready()

sql/rpl_group_replication.h

@@ -67,75 +67,4 @@ bool get_group_replication_group_member_stats_info(GROUP_REPLICATION_GROUP_MEMBE
 uint get_group_replication_members_number_info();
 
 
-/*
-  Server access methods and variables exported to plugin through
-  include/mysql/group_replication_priv.h
-*/
-/**
-  Returns if the server engine initialization as ended or not.
-
-  @return is the server ready
-    @retval false     not ready
-    @retval true      ready
-*/
-bool is_server_engine_ready();
-
-/**
-  Returns the server hostname, port and uuid.
-
-  @param[out] hostname
-  @param[out] port
-  @param[out] uuid
-*/
-void get_server_host_port_uuid(char **hostname, uint *port, char** uuid);
-
-/**
-  Returns a struct containing all server startup information needed to evaluate
-  if one has conditions to proceed executing master-master replication.
-
-  @param[out] requirements
- */
-void get_server_startup_prerequirements(Trans_context_info& requirements);
-
-/**
-  Returns the server GTID_EXECUTED encoded as a binary string.
-
-  @note Memory allocated to encoded_gtid_executed must be release by caller.
-
-  @param[out] encoded_gtid_executed binary string
-  @param[out] length                binary string length
-*/
-bool get_server_encoded_gtid_executed(uchar **encoded_gtid_executed,
-                                      uint *length);
-#if !defined(DBUG_OFF)
-/**
-  Returns a text representation of a encoded GTID set.
-
-  @note Memory allocated to returned pointer must be release by caller.
-
-  @param[in] encoded_gtid_set      binary string
-  @param[in] length                binary string length
-
-  @return a pointer to text representation of the encoded set
-*/
-char* encoded_gtid_set_to_string(uchar *encoded_gtid_set, uint length);
-#endif
-
-
-/**
-  Add thread to Global_THD_manager singleton.
-
-  @param[in] thd  The thread
-*/
-void global_thd_manager_add_thd(THD *thd);
-
-
-/**
-  Remove thread from Global_THD_manager singleton.
-
-  @param[in] thd  The thread
-*/
-void global_thd_manager_remove_thd(THD *thd);
-
-
 #endif /* RPL_GROUP_REPLICATION_INCLUDED */