Replace the hardcoded constants with a layout descriptor.
Replace the hardcoded constants with a layout descriptor.

A side effect is that the mares_darwinair_extract_dives function now
requires a valid device handle. This shouldn't cause any real problems
because this function will likely become private some day.

glance-/libdivecomputer,venkateshshukla/libdivecomputer,josh-wambua/libdivecomputer,venkateshshukla/libdivecomputer,Poltsi/libdivecomputer-vms,josh-wambua/libdivecomputer,glance-/libdivecomputer,henrik242/libdivecomputer,henrik242/libdivecomputer