This worklog provides support for:
  * retrieving P_S table definitions from performance schema engine
    and
  * for versioning of P_S table definitions.

To implement it the following modifications are done within the worklog:

  * A version of performance schema supported by server is stored in the table
    mysql.dd_properties as a value of property with the name "PS_version";

  * For every created P_S table a boolean property with the name
    "server_p_s_table" and the value "true" is stored in the column "options" of
    the table mysql.tables;

  * The P_S tables are recreated only in case a value of the property PS_version
    stored in Data Dictionary is different from the version of performance schema
    supported by server;

  * To recreate P_S tables, the "old" P_S tables are dropped and new ones
    are created;

  * To drop "old" P_S tables the metadata about all P_S tables stored in DD are
    fetched and those tables that contains the property with name
    "server_p_s_table" are dropped;

  * New P_S tables to be created are supplied by performance schema storage
    engine;

  * Every P_S table is defined in terms of instance of the class Plugin_table
    and embedded into server code;

  * The class Plugin_table is used to produce SQL statements for creation of
    P_S tables;

  * The classes Plugin_table, Plugin_table_impl were modified to allow optional
    setting of tablespace name for a table being created;

  * DDL SQL-statements for creation of server P_S tables were removed from
    the file mysql_system_tables.sql.