CheckVisibility returns true if rules are visible to packages.

IsValidDependency returns false if dep should not be used as a dependency.

JavaDependencyRuleKinds lists the kinds of Java rule that can be a dependency of a Java rule.

JavaEditableRuleKinds lists the kinds of rules that Jadep will edit.

RuleKindsToLoad lists the kinds of rules that Jadep requests from a PackageLoader server.

VisQuery represents the question, "is rule Rule visible to the package Pkg".