Clean Nucleus queue when removing an element

[norchow]

This was generating big memory leaks when creating and replacing
several components permanently.

[coveralls]

Coverage decreased (-1.0%) to 85.086% when pulling 5719eb5 on bitex-la:unqueue-removed-components into 6ed18a0 on intercellular:develop.

[norchow]

I would need some help with the tests to cover this issue.

Our real use case was like this:
We have 2 lists of ~100 items (rows of a list) each one, and they display near real-time data. So, when trying to re-render all these items over and over again, we discovered there was a memory leak in the Nucleus._queue, because it was not releasing outdated components.

Can anyone help me with the tests for this? I've tried integration, Nucleus and even Phenotype tests, but i cannot reproduce the case in which the components get overwritten either.

Thanks!