Objects in lists with a primitive property are tagged with ADDED if they are removed

[hheg]

Objects in lists with a primitive property are tagged with State.ADDED if they are removed. As seen in the PR #164 the test case.

I'm sorry if this didn't end up as a proper issue because I'm rather new at this, but I really like this library and use it extensively :) I haven't had the time to check if I can fix it myself, but I probably will.

[SQiShER]

Don't worry, the PR is great! Having a test to reproduce the issue always makes it so much easier. I can't promise how soon I'll be able to work on this, so feel free to give it a shot. I'd be happy to assist you with any questions that arise. 😃