BZip2/xz support for input files

[ipetrushin]

Dear SPAdes team!

Due to large FASTQ files may I ask for bzip2/xz compression support for input files?
.bz2 files up to 20-25% smaller than .gz, disk space on cluster is valuable and large data sets may not fit quotas.

Related benchmark paper https://www.biorxiv.org/content/10.1101/642553v2.full

Sincerely,
Ivan

[asl]

We may consider adding this is an option, yes, if the corresponding libraries are available on the system. Patches are always welcome :)