@param fn FASTA/FASTQ file name
@param fnfai Name of .fai file to build.
@param fngzi Name of .gzi file to build (if fn is bgzip-compressed).
@return 0 on success; or -1 on failure
If fnfai is NULL, ".fai" will be appended to fn to make the FAI file name.
If fngzi is NULL, ".gzi" will be appended to fn for the GZI file. The GZI
file will only be built if fn is bgzip-compressed.
@param fn FASTA/FASTQ file name @param fnfai Name of .fai file to build. @param fngzi Name of .gzi file to build (if fn is bgzip-compressed). @return 0 on success; or -1 on failure
If fnfai is NULL, ".fai" will be appended to fn to make the FAI file name. If fngzi is NULL, ".gzi" will be appended to fn for the GZI file. The GZI file will only be built if fn is bgzip-compressed.