Shared authorship

[lbulgarelli]

This adds a new shared authorship functionality when submitting projects.

• BaseAuthor and PublishedAuthor now have a shared field, which stores a number corresponding to a group of authors that contributed equally
• Logic for swapping authorship position was changed to account for shared authorship groups

[bemoody]

Thank you for working on this, Lucas. There are still some (mostly minor) issues here, and I realize you may not have any time to work on this further before you leave, but this is a good start and I hope we can get it integrated soon.

I'm following you, more or less, up to commit 2c0aa36.

After that... commit 4b0419f is mostly a stylistic change that seems unrelated to the rest of this series. There are some issues (PublishedAuthor.name is wrong; there's something funky going on with text_affiliations) but in terms of style it's a definite improvement.

Then we come to 36dcef1, and I have no idea what's going on and it seems to be broken. :P What is the intention here, and what is the logic?

[lbulgarelli]

After that... commit 4b0419f is mostly a stylistic change that seems unrelated to the rest of this series. There are some issues (PublishedAuthor.name is wrong; there's something funky going on with text_affiliations) but in terms of style it's a definite improvement.

Although this seems like just style changes, it was necessary I could use annotate. set_display_info sets attributes to the object, and those were overwritten after the annotate call, causing the information to be lost. This fixes that problem and also makes the code a bit cleaner :)

I made it so the properties would have the exact same value as was previously assigned set_display_info, to not unknowingly change something somewhere in the website, so idk a lot about name and text_affiliations. Did I change its behavior somehow or was it wrong before? Anyway, I can change it here if desired or open an issue.

Then we come to 36dcef1, and I have no idea what's going on and it seems to be broken. :P What is the intention here, and what is the logic?

So, in the first implementation, if an author was first in the group and I clicked his up button, the whole group would be moved up, changing position with the previous group/user. That was a bit confusing for the user, so instead, I introduced this change, that removes the up/down function for the first/last authors of a group. It should still be possible to move authors within their groups, which was not working but my last commit should've fixed it.