get_gel_num and get_contig_num

#include <IO.h>

int get_gel_num(
        GapIO  *io,
        char   *gel_name,
        int     is_name);

int get_contig_num(
        GapIO  *io,
        char   *gel_name,
        int     is_name);

These functions convert reading and contig names into reading and contig numbers. (A contig name is defined to be the name of any reading held within that contig.)

The is_name argument is mainly used for backwards compatibility. It should be passed as either GGN_ID or GGN_NAME. When equal to GGN_ID, gel_name is treated as a reading identifier, otherwise it is treated as a reading name. An identifier is defined to be either a reading name; a hash sign followed by a reading number; or an equals sign followed by a contig number.

Both functions return -1 for failure or the appropriate reading or contig number for success.