For applications supporting offline parsing (like libdivecomputer's own
dctool application), some device specific knowledge is still required in
order to map a particular model to the corresponding backend. The new
convenience function will take care of that internally.
The already existing dc_parser_new() function does the same, but
requires an open device handle, which makes it unsuitable for offline
parsing.
Libdivecomputer always uses metric units internally. But when reverse
engineering a device that stores everything using imperial units, it's
very convenient to be able to switch the output to imperial units too.
