my_checksum() mysys function
   NISAM checksum code moved from mysys to isam/ - it's obsolete
   MyISAM checksum code moved to mysys
   table's checksum accessible from sql layer
   SHOW TABLE STATUS shows checksum (WL#646)
code cleanup


include/my_sys.h:
  table checksum background: my_checksum() mysys function
include/myisam.h:
  table checksum background: my_checksum() mysys function
  MyISAM checksum code moved to mysys
isam/isamchk.c:
  table checksum background:
  NISAM checksum code moved from mysys to isam/ - it's obsolete
isam/isamdef.h:
  table checksum background:
  NISAM checksum code moved from mysys to isam/ - it's obsolete
isam/open.c:
  table checksum background:
  NISAM checksum code moved from mysys to isam/ - it's obsolete
isam/pack_isam.c:
  table checksum background:
  NISAM checksum code moved from mysys to isam/ - it's obsolete
myisam/mi_checksum.c:
  table checksum background: my_checksum() mysys function
  MyISAM checksum code moved to mysys
mysys/checksum.c:
  table checksum background: my_checksum() mysys function
  MyISAM checksum code moved to mysys
sql/ha_myisam.cc:
  table checksum background: table's checksum accessible from sql layer
sql/ha_myisam.h:
  table checksum background: table's checksum accessible from sql layer
sql/handler.h:
  table checksum background: table's checksum accessible from sql layer
  code cleanup
sql/sql_lex.h:
  table checksum background: table's checksum accessible from sql layer
  code cleanup
sql/sql_select.cc:
  warning removed
sql/sql_show.cc:
  SHOW TABLE STATUS shows checksum (WL#646)
sql/sql_yacc.yy:
  cleanup
  (DROP TABLES syntax added as a side effect :))