@param p pileup data
@param ins the kstring where the insertion sequence will be written
@param del_len location for deletion length
@return the length of insertion string on success; -1 on failure.
Fills out the kstring with the padded insertion sequence for the current
location in 'p'. If this is not an insertion site, the string is blank.
If del_len is not NULL, the location pointed to is set to the length of
any deletion immediately following the insertion, or zero if none.
@param p pileup data @param ins the kstring where the insertion sequence will be written @param del_len location for deletion length @return the length of insertion string on success; -1 on failure.
Fills out the kstring with the padded insertion sequence for the current location in 'p'. If this is not an insertion site, the string is blank.
If del_len is not NULL, the location pointed to is set to the length of any deletion immediately following the insertion, or zero if none.