- make the client to respect the server-side 
   no_backslash_escapes option and disable the 
   special meaning of backslash also at client side.


mysql-test/r/mysql_client.result:
  Bug #20103: Escaping with backslash does not work
   - test case
mysql-test/t/mysql_client.test:
  Bug #20103: Escaping with backslash does not work
   - test case