gnu: preseq: Update to 2.0.

* gnu/packages/bioinformatics.scm (preseq): Update to 2.0.
[source]: Add file-name field, remove patches.
[arguments]: Remove unused build phases, add make flags.
[inputs]: Add smithlab-cpp.
* gnu/packages/patches/preseq-1.0.2-link-with-libbam.patch: Remove file.
* gnu/packages/patches/preseq-1.0.2-install-to-PREFIX.patch: Remove
  file.
* gnu-system.am (dist_patch_DATA): Remove them.