This adds support for older Cochran Commander dive computers,
specifically Commanders with serial numbers prior to 21000.
This also renames "Commander" model to "Commander II" and
adds "Commander I" to refer to pre-21000 models.
Since commit 344bfab229a17c7227b9bec02f616505a8d9e998 only a subset of
the id string is used to detect the model. But because the offset was
never updated, the model detection always fails now.
The vendor_product_parser_create() and vendor_product_device_open()
functions should be called indirectly, through the generic
dc_device_open() and dc_parser_new() functions. And the
vendor_product_extract_dives() functions are internal functions that
should never have been part of the public api in the first place.
The low level serial and IrDA functions are modified to:
- Use the libdivecomputer namespace prefix.
- Return a more detailed status code instead of the zero on success and
negative on error return value. This will allow to return more
fine-grained error codes.
- The read and write functions have an additional output parameter to
return the actual number of bytes transferred. Since these functions
are not atomic, some data might still be transferred successfully if
an error occurs.
The dive computer backends are updated to use the new api.
