Major Description
Some of the tests in org.apache.jackrabbit.oak.kernel are not related to the kernel implementation but rather general node store tests. Also the functionality provided by OakBaseTest is somewhat duplicated by AbstractKernelTest and also duplicated in NodeStoreTests and CheckpointTest.
I like to clean this up a bit by making all tests use OakBaseTest and move the respective tests in org.apache.jackrabbit.oak.kernel to org.apache.jackrabbit.oak.spi.state. At the same time I'd like to add the MemoryNodeStore fixture to all test so the memory node store gets some more test exposure.