Rename JsRules to JsRunner.

Rules classes are generally the actual rules namespaces we use. This is
more of a generic javascript runner.
Move Enforcer classes into the entitlement package.
Rename JsRulesProvider to JsRunnerProvider.
Rename JsExportRules to just ExportRules.
Remove unused PoolRules interface.
Rename to CriteriaRules to match other rules classes.
Remove duplicate imports.
Merge pull request #160 from candlepin/dgoodwin/rules-class-cleanup

Dgoodwin/rules class cleanup