Add report_workspace() to Reporter, and remove dead rules from the workspace.

I think the change to `workspace.breakRule()` is harmless. In theory, it
should make Copycat less hesitant to come up with rules that conflict with
the already-broken rule.

copycat/codeletMethods.py

@@ -837,7 +837,7 @@ def rule_builder(ctx, codelet):
     rule.updateStrength()
     assert rule.totalStrength
     # fight against other rules
-    if workspace.rule:
+    if workspace.rule is not None:
         assert __structureVsStructure(rule, 1.0, workspace.rule, 1.0)
     workspace.buildRule(rule)