Fix PolicyRegistrationTest.testRemoveAllPolicies
Merge pull request #583 from aledsage/fix/PolicyRegistrationTest

Fix PolicyRegistrationTest.testRemoveAllPolicies
Adds EntityDriverRegistry

- managementContext.getEntityDriverFactory() returns EntityDriverRegistry
- EntityDriverRegistry extends EntityDriverFactory, and exposes
  registerDriver(...)
EntityDriverManager: incorporate feedback

- Deprecate EntityDriverFactory
- Rename EntityDriverRegistry to EntityDriverManager