include/my_sys.h:
  make [un]lock_io_cache functions, not macro
  some io_cache_share functions int->void
include/myisam.h:
  mi_repair_by_sort_r -> mi_repair_parallel
  MI_SORT_PARAM.master field for updating info->s.state struct
myisam/mi_check.c:
  mi_repair_by_sort_r -> mi_repair_parallel
  MI_SORT_PARAM.master field for updating info->s.state struct
myisam/sort.c:
  my_thread_init()/my_thread_end()
  misc bugfixes
mysys/mf_iocache.c:
  io_cache_share functions int->void
  comments added
  [un]lock_io_cache functions added