Fix incorrect conditions in pairsOf

Fixes ticket 435
Don't show kernel fields as "Bool" in diagram
Use --test for DataAnalysis
Refactor classes computation to use local variable
Cleanup + Typo
Use rootOf for targets in binary tables (like we do for wide tables)
Remove Either from source and target in Association

Both are always a class name now. Using concepts here caused problems when tables where renamed for uniqueness. Also, filter on hasKernelTaget was redundant, since this is already guaranteed by the construction of the Associations.
Filter classes with fewer than 2 attributes (and assocs between them)