io_read_annotation and io_write_annotation

#include <IO.h>

int io_read_annotation(
        GapIO  *io,
        int     N,
        int    *anno);

int io_write_annotation(
        GapIO  *io,
        int     N,
        int    *anno);

These functions read and write the first annotation number in the linked lists referenced by the reading and contig structures. For both functions, N is a reading number if it is above zero or a contig number when below zero (in which case it is negated).

io_read_annotation reads the annotations field of reading N or contig -N and stores this in anno. It sets anno to 0 returns 1 for failure. Otherwise it returns 0.

io_write_annotation sets the annotations field of reading N or contig -N to be *anno. Despite the fact that it is a pointer, the contents of anno is not modified. It returns 1 for failure and 0 for success (but currently always returns 0).