There were two versions of the insert_trip() function: one
would merge trips if a trip with the same date already existed,
the other wouldn't. The latter was introduced with the dive-list
undo work.
The problem is that the "date" of a trip (i.e. the first dive)
seems ill-defined as this is a volatile value. Moreover in
the context of making dive-import undoable this is a very
dangerous notion, as the caller needs control over when the dives
are added to a trip.
Therefore, unify these two functions and never merge trips.
The decision on merging dives now has to made by the caller.
This will be implemented in a future commit.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
0618aa737f