Aggregate results can now be filtered for each show type, so
can do stuff like get_aggregateresults(sum.results,2) for one
show type
Merge branch 'showresultgrouping'
note added in contig evolution and by show type filtering

*by show filtering option on get agg results
*method to filter an agg results class by show type
*note added into contig evolution, adding distinction between it and the
contig static