* rules/bio/ngs/tools/gatk.rules:
  - add picard.rules
  - update VariantEval options; GenotypeConcordance has been moved to own walker, remove redundant -ST spec
* rules/bio/ngs/report.rules: add plots, csv-table support, and remove dependency on texttable.
* snakemakelib/report/picard.py: add width spec to make_rst_table, fix error in add_column