The deisgn decision to have only one instance of QueryTemplate
leads to the necessity to keep AspectClique separated for
every "typesystem". Whereas QueryTemplate are really perfectly
composable, and thus only one AspectClique is neeeded.
Also drop a rudimentary unused feature.
Treat a language and its sidekick (if any) as a single vertex.
Add all extended languages to the pool before building the graph.
Drop dubious invariant check.
Fix the second pass in findAspectCliques ingnoring the fact
that there might be leafs without aspects.
Fedor Isakov