Type resolver changed to use good flow inference.
Retired SymbolTable.

SymbolTable test is now an ImportedNameTypeTest.
Fix NamespaceName goal to include names bound by intermediate
import.
Build intermediate import binding table once, not on demand.
Reuse the same engine for all phases of the analysis.

This massively speeds things up (i.e. gets things back to the speed they
were running at before unifying the backing CFA engine) as results are
reused.
Support Top result for duck analysis.
Revert "Build intermediate import binding table once, not on demand."

This reverts commit 2f039623c1885f7fa126f4737e59581cb893f1f7.
Process all call sites when diffing.
Only duck-analyse attributed calls (again).

And hack it so we don't do this when the LHS is a module.  That breaks
it.
Add reminder to fix loading of os.path.
Make single-level relative imports work.

Multiple-level still to do.  Tests written for those fail.
Fixed multi-level relative imports.
Fixed major bug where any subscript would kill flow analysis.
Fleshed out builtins.
Fix flow of names in the builtin namespace.
Add class as well as instance types when duck-typing.
Prevent inheritance from 'object' screwing up constructor argument flow.
Fix FunctionObjectNamespace equality.
Make ClassCO constructor private.
Fix dummy namespace equality to ensure termination.