=====================================
Enhance server clone plugin created in WL#9209 to transfer snapshot
over network from one mysqld instance to another. Clone plugin
installed in both severs accomplishes the data capture, transfer
and apply.

This feature would be used in future to provision a replica node
by cloning the snapshot from one of the nodes in a replication
group. It is one of the child worklogs of wl#8953.

[Donor]: mysqld server that provides the snapshot
-------
INSTALL PLUGIN clone SONAME 'mysql_clone.so';
CREATE USER clone_user IDENTIFIED BY 'clone_password';
GRANT BACKUP_ADMIN on *.* to clone_user;

[Recipient]: mysqld server that receives the snapshot.
-----------
INSTALL PLUGIN clone SONAME 'mysql_clone.so';
     CLONE INSTANCE FROM clone_user@HOST:PORT
     IDENTIFIED BY 'clone_password'
     DATA DIRECTORY [=]'<clone directory>'
     [REQUIRE [NO] SSL];

clone_user     : User name to connect to donor mysqld server
clone_password : Password for the User
HOST           : The host where donor server is running
PORT           : Classic protocol PORT of donor server
DATA DIRECTORY : Recipient directory for cloned data

Reviewed-by: Gleb Shchepa <gleb.shchepa@oracle.com>
Reviewed-by: Marcin Babij <marcin.babij@oracle.com>

RB: rb#19143