Minor. Satisfy code analysis, remove some using statements.
(Probably breaking tests) Remove the ICryptographyService extensibility point which was not being used for anything.
(Fixing tests) broken by previous commit for removing ICryptographyService extensibility point. And somehow I need to change an Assert.False to Assert.True in WebMatrixPackageCuratorFacts.cs which really doesn't seem right. Did I break that last time? Yes, indeed I did. It used to verify creation method was 'called once'.