A) This WL aim to provide following functionality:

  1) Enforce table encryption globally:

  Enable all tables to be encrypted by default. Add global system
  variable 'default_table_encryption'.

  2) Force encryption for certain database:

  Enable all tables in the specific database be encrypted by
  default. Add new DEFAULT ENCRYPTION clause for database to
  support the same.

  3) Disable encryption globally:

  Disable tables encryption in MySQL by default. The system
  variable 'default_table_encryption' enables the same.  This is
  helpful to avoid double encryption since underlying storage is
  encrypted already in cloud setup.

  4) Backward compatible setup:

    Keep CREATE TABLE ... ENCRYPTION=Y|N and
    CREATE TABLESPACE ENCRYPTION=Y|N work as before.

B) Major changes done are:

  1) Support DEFAULT ENCRYPTION property for DATABASE.
    - Add new column to mysql.schemata.
    - Add mysql.schemata.default_encryption ENUM('NO','YES') dd column.

  2) Support new privilege TABLE_ENCRYPTION_ADMIN.

  3) Add two system variables,

    a. The system variable to control global encryption default.
       --default-table-encryption=Y|N.
       - Add Session/Persistable system variable 'default_table_encryption'.

    b. The option which indicates whether we do privilege check.
       --table-encryption-privilege-check=Y|N.
       - Add Global/Persistable system variable
         'table_encryption_privilege_check'.

  4) Change implementation of following command to behave as per above
     requirement defined by three options. Detailed behavior change is
     described in WL.

    CREATE|ALTER DATABASE ...
    CREATE|ALTER TABLESPACE ...
    CREATE|ALTER TABLE ...
    RENAME TABLE ...

  5) Add new column to
     INFORMATION_SCHEMA.SCHEMATA.DEFAULT_ENCRYPTION to show value
     supplied in new clause added by 1) above.
    - Change I_S.TABLES.CREATE_OPTIONS to show ENCRYPTION clause only if table
      is encrypted or if encryption is different than the schema encryption
      default.

  6) Upgrade from 8.0/5.7 to wl12261 version causes updates ENCRYPTION
     clauses for schema/tablespaces/tables and table as discussed in HLS.
    - Added Internal functions GET_DD_PROPERTY_KEY_VALUE() and
      REMOVE_DD_PROPERTY_KEY(). This is used during 8.0->8.0 upgrade.

  7) Increase dictionary and INFORMATION_SCHEMA version as we modify both
     of these definitions.

  8) Introduce HTON_SUPPORTS_TABLE_ENCRYPTION flag for handlerton. Enabled
     it to InnoDB for now.

  9) Group replication code is changed to ensure 'default_table_encryption'
     value is same across all GR nodes. We write value of global
     'default_table_encryption' in binlog for DDL's listed in 4).

 10) Added tests in new test suite encryption. Changes are done in ndb, rpl,
     keying_aws suite too.
     - Have modified tests to allow CREATE TABLE succeed by adding explicit
       ENCRYPTION clause when using encrypted general tablespaces.

 There are several other changes done in this WL. Refer the WL page for
 more details.

 The code is reviewed by:
   Praveen - Server changes,
   Sivert - Upgrade changes,
   Mayank - InnoDB changes,
   Hemant Dangi - Replication changes,
   Gleb - Parser changes.

Change-Id: I77221ec45bea509347b8a612b8510dea318d5d3b