Renamed presence back to dirt.
Dirt now contains regions instead of presences.
Removed the Constraints.Region bound.
We print out variable types on top lets.
Top recursive functions are given appropriate names.
Corrected let inference.
We keep track of top context and constraints.
Type constraints are a disjoint union of graphs.
Let inference seems to work, but I don't know why.
Added printing of skeletons.
One more fix in top-level contexts.
Moved repmin.eff to examples (its proper place)
We keep constraints between things in context.
Reverted to old syntax tests.
Added collapsing of skeletons.
Enabled old-style printing.
Validated tests that work better than before.
Simplified let-inference.
Cleaned up Infer.infer_pattern.
Cleaned up Infer.infer_expr (except for handlers)