The second variant of the open or create functions were introduced to
maintain backwards compatibility. But after being removed from the
public api, these functions serve no purpose anymore, and can be removed
completely.
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 public header files are moved to a new subdirectory, to separate
the definition of the public interface from the actual implementation.
Using an identical directory layout as the final installation has the
advantage that the example code can be build outside the project tree
without any modifications to the #include statements.
Although calibration is optional, it's highly recommended because it
reduces the transfer time considerably. The calibrate function is
removed from the public api.
