Remove layout.module from core

If we're going to do this, I'd rather do it asap rather than later. Removing a module is considerably harder than adding one. Once we get to beta we'll support beta-beta upgrade paths - so what happens if we remove the module on a site that has it enabled?

This is a simple git rm -r core/modules/layout. I grepped for "layout" in core and couldn't find anything related.
modularity++

Dries agreed to postpone this to give SCOTCH folks more time, so it seems like he should be the one to commit the patch if he feels enough time has passed.

Just wondering, if this makes sense when we do start using it with the #2055853: [meta] Improve the place block UX; Separate interaction from the create block UX; Improve the existing blocks-by-theme layout. This needs some more management.

We're not using it. That issue is about "Improve the existing blocks-by-theme layout". Not "Improve the existing blocks-by-layout layout".

@Bojhan: Perhaps you meant #1787956: Make blocks relate to layout instances instead of themes, but that got pushed to D9 recently.

I just committed #1978910: Convert layout_page_view to a Controller, so this'll need a re-roll.

Probably fine to go straight back to RTBC on this. If 'bot disagrees, it'll kick it back.

Committed to 8.x. Thanks. Sad to see the module go but we can add it back in in Drupal 9.

What should we do with https://drupal.org/node/1813372 now, delete? edit? Post a new one?

Has to be either delete + new one or edit the existing one for change notice, not sure which is best.

I vote for delete + new so that it gets to https://twitter.com/drupal8changes, RSS, etc.

Do we have to reopen #1787846: Themes should declare their layouts and move it to D9?

I think so yes, I also support deleting the old CN and adding a new one that documents this change. No one should come across the old one while trying to upgrade their modules to D8. (we might want to consider some sort of "removed" tag for any other instance of CN's who's underlying code has been removed?)

Eclipse

Cool URIs don't change

I just blanked the date to put it back at the top of the list with "[REVERTED]" in the title, and gave a pointer to https://drupal.org/project/layout. Also moved all the active layout.module issues there and will delete the component in a sec.

I'll go commit the old code from D8 core to the contrib project there momentarily.