The following changes are included:
+ Add dev_type to devinfo_t
+ Add b_cmd to bufinfo_t
+ Add constants for BIO_* and DEVSTAT_TYPE_*
+ Add inline for converting BIO_* int to string
+ Add inline for converting DEVSTAT_TYPE_* int to string
+ Add mask for dev_type & DEVSTAT_TYPE_MASK to string
+ Add mask for dev_type & DEVSTAT_TYPE_IF_MASK to string