ha_berkeley.
A few smaller bug fixes.


sql/ha_berkeley.cc:
  - Don't use subtransactions on write_row() and delete_row()
  - Bug fixes for sharing DB *file
sql/ha_berkeley.h:
  - Don't use subtransactions on write_row() and delete_row()
  - Bug fixes for sharing DB *file
sql/ha_myisam.cc:
  - fix compiler warning
sql/log_event.cc:
  - fix compiler warning