Added ORDER BY optimization


Docs/manual.texi:
  Added ORDER BY optimisation section
heap/_check.c:
  Cleanup
heap/heapdef.h:
  Added support of null keys in HEAP tables
heap/hp_hash.c:
  Added support of null keys in HEAP tables
heap/hp_open.c:
  Added support of null keys in HEAP tables
heap/hp_test2.c:
  Added support of null keys in HEAP tables
heap/hp_write.c:
  Added support of null keys in HEAP tables
include/heap.h:
  Added support of null keys in HEAP tables
include/my_base.h:
  Support for hash algoritm
isam/static.c:
  Cleanup
myisam/mi_static.c:
  Cleanup
sql/Makefile.am:
  Rename innobase -> innodb
sql/ha_berkeley.cc:
  Added ORDER BY optimization
sql/ha_berkeley.h:
  Added ORDER BY optimization
sql/ha_heap.cc:
  Added support for NULL keys
sql/ha_heap.h:
  Added support for NULL keys
sql/ha_isam.cc:
  Added ORDER BY optimization
sql/ha_isam.h:
  Added ORDER BY optimization
sql/ha_isammrg.h:
  Added ORDER BY optimization
sql/ha_myisam.cc:
  Added ORDER BY optimization
sql/ha_myisam.h:
  Added ORDER BY optimization
sql/ha_myisammrg.cc:
  Added ORDER BY optimization
sql/ha_myisammrg.h:
  Added ORDER BY optimization
sql/handler.cc:
  Rename innobase -> innodb
sql/handler.h:
  Rename innobase -> innodb
sql/ha_innodb.cc:
  Rename innobase -> innodb
sql/ha_innodb.h:
  Rename innobase -> innodb
sql/mysqld.cc:
  Rename innobase -> innodb
sql/sql_delete.cc:
  Rename innobase -> innodb
sql/sql_select.cc:
  Added ORDER BY optimization
sql/sql_select.h:
  Added ORDER BY optimization