Merge april.(none):/home/svoj/devel/mysql/BUG20256/mysql-5.0-engines

into  april.(none):/home/svoj/devel/mysql/BUG20256/mysql-5.1-engines


sql/ha_myisam.cc:
  Auto merged
sql/ha_myisam.h:
  Auto merged
sql/handler.cc:
  Auto merged
BitKeeper/deleted/.del-index_merge.result:
  Auto merged
mysql-test/include/index_merge1.inc:
  Manual merge.
sql/handler.h:
  Manual merge.
sql/opt_range.cc:
  Manual merge.

sql/handler.h

@@ -942,6 +942,7 @@ public:
   {
     /* TODO: DBUG_ASSERT(inited == NONE); */
   }
+  virtual handler *clone(MEM_ROOT *mem_root);
   /* This is called after create to allow us to set up cached variables */
   void init()
   {