biology/flash: Fast Length Adjustment of SHort reads

FLASH (Fast Length Adjustment of SHort reads) is a very fast and
accurate software tool to merge paired-end reads from next-generation
sequencing experiments. FLASH is designed to merge pairs of reads when
the original DNA fragments are shorter than twice the length of reads.
The resulting longer reads can significantly improve genome assemblies.
They can also improve transcriptome assembly when FLASH is used to
merge RNA-seq data.