WIP Quantity masked array - #6005

@mhvk - I had a quick look. Do you think the problem with MaskedArray * unit is solvable?

@taldcroft - it turns out in numpy >=1.10, the MaskedArray * unit problem is solved; presumably, some work-around would be possible for 1.9. But really I should look at your PRs, and think more about the implication of possibly having NaN in the arrays.

Hi humans 👋 - this pull request hasn't had any new commits forapproximately 5 months. I plan to close this in a month if the pullrequest doesn't have any new commits by then.

In lieu of a stalled pull request, please consider closing this and open anissue instead if a reminder is needed to revisit in the future. Maintainersmay also choose to add keep-open label to keep this PR open but it isdiscouraged unless absolutely necessary.

If this PR is still needed to be reviewed, as an author, you can rebase itto reset the clock. You may also consider to send a reminder e-mail about itto the astropy-dev mailing list.

If you believe I commented on this pull request incorrectly, please report this here.

⏰ Time's up! ⏰

I'm going to close this pull request as per my previous message. If you think what is being added/fixed here is still important, please remember to open an issue to keep track of it. Thanks!

If this is the first time I am commenting on this issue, or if you believe I closed this issue incorrectly, please report this here.