- added patch from Dominic to unlock the ATMEL flash in cfi_read_atmel_pri_ext

- set cfi_info->write_algorithm and cfi_info->erase_check_algorithm to NULL to 
  get "flash erase_check" command working

git-svn-id: svn://svn.berlios.de/openocd/trunk@227 b42882b7-edfa-0310-969c-e2dbd0fdcd60