Allows selected to be set using index, even if attr-for-selected is used

[graeme44]

This closes #87.

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[graeme44]

I signed it!

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CLAs look good, thanks!

[bicknellr]

Thanks for the PR! This needs to be implemented in IronMultiSelectableBehavior + tested.

[bicknellr]

.. also rebased apparently? Weird for such a self-contained PR.

[bicknellr]

@graeme44, you there? Just wanted to give you a heads up that I'm going take over adding this feature soon - probably before the end of the week. If you'd prefer to keep maintaining this PR, please leave a comment.

[graeme44]

@bicknellr, that sounds good! I'm happy for you to take over.

[bicknellr]

Ok, I just created a new branch, issue-87, pointing to the same commit as current master. Could you rebase and change the base branch for this PR to that so that I can pull your commits into it?

[graeme44]

@bicknellr, Rebase done.

[bicknellr]

@graeme44, just one more step: could you open a new PR with 'issue-87' as the base branch? I thought there was a way to change this on an open a PR but some quick searching seems to imply otherwise.

[bicknellr]

Oh, forgot to close this after merging #110.