called from a SELECT doesn't cause ROLLBACK of state"
Make private all class handler methods (PSEA API) that may modify
data. Introduce and deploy public ha_* wrappers for these methods in 
all sql/.
This necessary to keep track of all data modifications in sql/,
which is in turn necessary to be able to optimize two-phase
commit of those transactions that do not modify data.


sql/ha_partition.cc:
  Class ha_partition is no longer a friend of class handler.
  Use the public handler interface (handler::ha_ methods) for partition
  operations.
  Remove unnecessary casts from char[] to const char *.ppзи выафвыаafa
sql/handler.cc:
  Function ha_create_table() is no longer a friend of class handler.
  Use public handler::change_table_ptr() to access private members.
  This fixes a subtle bug (no test case in the test suite) when a
  deletion error occurs inside one partition of a partitioned engine. 
  The old code would crash in handler::print_error() in this case.
  
  Implement the newly introduced public ha_* wrappers of the private
  virtual handler methods.
sql/handler.h:
  Introduce ha_* wrappers to all class handler methods that may
  modify data. This is necessary to be able to keep track of
  data modifying operations of class handler and optimize read-only
  transactions.
sql/item_sum.cc:
  delete_all_rows -> ha_delete_all_rows
sql/sql_base.cc:
  Use the new public wrappers.
sql/sql_delete.cc:
  delete_all_rows -> ha_delete_all_rows
sql/sql_partition.cc:
  Use the new public wrappers.
sql/sql_select.cc:
  delete_all_rows -> ha_delete_all_rows
  delete_table -> ha_delete_table
  disabe_indexes -> ha_disable_idnexes
sql/sql_show.cc:
  delete_all_rows -> ha_delete_all_rows
sql/sql_table.cc:
  Use the public wrappers for class handler DDL methods.
  All methods which may change handler data are now accessed via a public
  wrapper.
sql/sql_union.cc:
  delete_all_rows -> ha_delete_all_rows
  {enable,disable}_indexes -> ha_{enable,disable}_indexes
sql/sql_update.cc:
  bulk_update_row -> ha_bulk_update_row
sql/unireg.cc:
  create_handler_files -> ha_create_handler_files