Parameterized option to create unique subdirectory for each RoiSet, but this still isn't propagating to dataframe called in .serialize

# Conflicts:
#	model_server/base/api.py
#	model_server/base/roiset.py
#	tests/base/test_roiset_pipeline.py

RoiSet.run_exports and .get_export_product_accessors no longer take a channel directly, but rather pull these from parameters of individual patch products

Requirements for building on cluster

See merge request rhodes/model_server!79

# Conflicts:
#	tests/base/test_roiset_pipeline.py

Updated tests: smoothing is now more aggressive, lowered threshold of IOU for comparison; task endpoints updated

Updated tests: smoothing is now more aggressive, lowered threshold of IOU for comparison; task endpoints updated

Default assume that accessors are not lazy; add_accessor then overrides this if a lazy accessor is subsequently bound to this ID