whdenovo simulate (illumina or pacbio) generate lots of temporary files and whdenovo simulate pacbio only outputs reads from the first scaffold

[jelber2]

I noticed that whdenovo simulate illumina generates lots of temporary files that don't seem to be needed if you then use whdenovo simulate pacbio. This isn't a problem for small genomes, but for 1 Gbp genomes, the temporary files can quickly take up to nearly 1 TB. Also, whdenovo simulate pacbio makes a lot of temporary files and only takes the first scaffold in a multi-scaffold FASTA. I could submit a pull-request, but this might take sometime.