Backport of functionality in private 5.2 tree. 

Added new language to parser, new mysql.servers table and associated code
to be used by the federated storage engine to allow central connection information
per WL entry.


libmysqld/Makefile.am:
  WL# 3031
  
  Added sql_servers.cc to libmysqld Makefile.am
mysql-test/lib/init_db.sql:
  WL# 3031
  
  Added mysql.servers creation to init_db.sql, which is in turn called by mysql-test-run.pl
scripts/mysql_create_system_tables.sh:
  WL# 3031
  
  Added mysql.servers table creation to script called by non-perl mysql-test-run
sql/Makefile.am:
  WL# 3031
  
  Added sql_servers source and headers to Makefile.am to be built
sql/lex.h:
  WL# 3031
  
  Added tokens needed for SERVERS scheme
sql/mysql_priv.h:
  WL #3031
  
  Added sql_servers.h to mysql_priv.h so mysqld.cc and other code can link with sql_servers code
sql/mysqld.cc:
  WL# 3031
  
  Added servers_free and servers_init to mysqld
sql/sql_lex.cc:
  WL# 3031
  
  Added lex->server_options parameter initialisation
sql/sql_lex.h:
  WL #3031
  
  Added SQLCOM commands needed for sql_server actions
sql/sql_parse.cc:
  WL# 3031
  
  Added switch actions for new SQLCOM sql_server actions
sql/sql_yacc.yy:
  WL #3031
  
  Added tokens needed for sql_servers, CREATE/DROP/ALTER server functionality
sql/share/errmsg.txt:
  WL# 3031
  
  Added two new errors to errormsg.sys
storage/federated/ha_federated.cc:
  WL #3031
  
  Modified federated storage engine to use new connection scheme (servers 
  table) if connection string only specifies connection name vs. complete
  URL
storage/federated/ha_federated.h:
  WL# 3031
  
  Added new share members needed for connection scheme
sql/sql_servers.cc:
  WL #3031
  
  sql_servers.cc - all methods required for manipulating mysql.servers table
  to work with federated new connection scheme (CREATE/ALTER/DROP SERVER ...)
sql/sql_servers.h:
  WL #3031
  
  New header file for sql_servers functionality
mysql-test/r/federated_server.result:
  WL #3031
  
  New test results for testing new connection scheme
sql/sql_yacc.yy.bak:
  WL #3031
  
  Added tokens and definitions required for new CREATE/ALTER/DROP SERVER
  for sql_servers functionality. See WL for details.
mysql-test/t/federated_server.test:
  WL #3031
  
  New test for testing CREATE/ALTER/DROP SERVER, as well as testing that
  federated works with both tradition connection scheme as well as new
  connection scheme.