This step introduces a new option to rotate the binlog encryption master
key at server startup.

It also contains a refactored include/rpl_get_log_encryption_key_id.inc
and rpl.rpl_encryption test case.

Re-recorded test cases because of the new privilege introduced by this
work and also because of the new column in SHOW BINARY|MASTER LOGS
output are also present in this step.

@ share/errmsg-utf8.txt

  Introduced the following errors:
  - ER_SERVER_RPL_ENCRYPTION_UNABLE_TO_ROTATE_MASTER_KEY_AT_STARTUP;
  - ER_SERVER_RPL_ENCRYPTION_IGNORE_ROTATE_MASTER_KEY_AT_STARTUP;

@ sql/rpl_log_encryption.{h|cc}

  Added the support for the new option to rotate the master key at
  server startup.

@ sql/sys_vars.cc

  Introduced the binlog_rotate_encryption_master_key_at_startup option.

Test case
=========

@ rpl.rpl_encryption_master_key_rotation_at_startup

  This test case will enable binlog encryption master key rotation on
  server startup forcing some failures to exercise the binlog encryption
  master key recovery process.

@ sys_vars.binlog_encryption

  Basic testing for the new global dynamic variable.

@ sys_vars.binlog_rotate_encryption_master_key_at_startup

  Basic testing for the new global read only variable.