Add support for the new DX data format.
Add support for the new DX data format.

Just like the D4i and D6i, the new header is a few bytes larger. The
correct variant can again be detected by means of the logbook id tag at
the start of the header.

henrik242/libdivecomputer,henrik242/libdivecomputer,Poltsi/libdivecomputer-vms,glance-/libdivecomputer,glance-/libdivecomputer