[jbond] Clean up mocking capabilities

[xkrogen]

Currently Java has mocking capabilities through PowerMock, but they require a sizable amount of ugly setup code on each test (see http://necula01.github.io/bond/jbond/bond/spypoint/BondMockPolicy.html). There may be ways to reduce this; we should investigate further.

[xkrogen]

One idea is to see if we can dynamically inject some of the annotations at runtime; I plan to investigate how feasible this is.