I'll comment only one thing now:
It looks like you created a brand new repository instead of starting from a clone of the existing libdivecomputer repository. That makes it very difficult to see what you changed.
Yes, blasted!
I'll fix that first, then it will probably be easier to continue the discussion.
Please ignore any pull/push requests, I'm new to git so I may trigger something inadvertently mucking around.
Poltsi