Found another class that accesses a file in its static initializer, and
so must be pre-initialized.
Introduced an AssetContainer.scopeAssetContainers() method, so that the
trie we build need only contain classes that are actually reachable from
a particular source module (blades shouldn't be able to refer to aspect
classes for example), plus re-enabled some tests that I
temporarilly disabled in an earlier commit.