This is round 2 of #3801.

It mitigates/fixes #503 and fixes #2024.

What remains to be done in this branch is:

- Make sure the text is translatable, right now it's hardcoded to "Edit Post"
- Make sure the text is contextual (so it shows Edit Page, Edit CPT etc)

This just uses the stock WordPress objects.

Adds test cases to fully cover the REQUEST_POST_UPDATE_SUCCESS effect.

This changes the opacity of a disabled button to be .3 opacity from .6 previously. This fixes #3928

…st-post-update-success

Add full coverage for REQUEST_POST_UPDATE_SUCCESS effect.

… to be mounted (#4002)

Try fainter disabled state

Fix blocks when useOnce is true

Components: Add withState higher-order component

Block API: Refactor supportHTML as supports property

…dynamic

Make the block settings menu item dynamic

…dit-block

Blocks: Move logic for generating class name to BlockEdit component

Audio Block: Changes edit buttonProps to html attributes

This mechanism allows treating elements as inline if they are being pasted in specific tags. So for example in heading blocks we can interpret headings as inline content and on lists we can interpret lists as inline content.

…ps mechanism.

This improves the behaviour of paste in already existing list and heading blocks.

…lineForTag mechanism.

Update to Jest v22.0.1

… withAPIData HoC in latestPosts.

An intermediary step to use withAPIData.

…with withAPIData HoC in Categories Block.

Categories block was the only block in our codebase that uses wp.api…, this change makes the block more inline with the rest of the codebase.

* Add dynamic block documentation

Taken from https://riad.blog/2017/10/16/one-thousand-and-one-way-to-extend-gutenberg-today/#dynamic-block.

* Add ES6 JavaScript code example

* Add a title to dynamic blocks doc entry

* Fix some small grammar errors

* Remove Riad from the code examples 😉

* Fix typo in dynamic block documentation

This is a suggestion for #4080. It increases the 2 columns to 3 for the inserter.

Those controls include the mover and the ellipsis menu. As such, this PR fixes #4084.

What this PR does, is remove all mobile tools from the quick toolbar, and instead shows these tools inline at the bottom of a _selected_ block.

…k's markup

Props @maddisondesigns for text.

Fixes #2956.

This renames the "Classic Text" block to just "Classic", because it can do more than just text.

…reducer only

Adds in a wider inserter.

The left align wasn't working so lets move border and center align.

…nberg into try/improved-mobile-tools

…ription

Improve paragraph block description.

Try improving mobile controls

That is, scroll the `html` element, instead of a specially dedicated area. Although the latter has a ton of benefits, the former is the only thing that works stably on Mobile Safari. The thing is, there's overscroll bounce that you can't really turn off, so if you aren't scrolling the main content area things are just going to be all kinds of janky.

Also rotate ellipsis so it matches top toolbar one.

Rename "Classic Text" to "Classic". Props @jasmussen

3 column inserter

- Add padding when fixed toolbar is enabled so the white sheet doesn't cover the permalink bar
- Fit the permalink bar snugly to the screen edges on mobile

Polish mobile, notably iPhone

#3895 showed there was an issue with SuperAdmins not having a role on a site of a multisite network. After some discussions, we think it is best to check the post type capabilities for the connected user and the current post type being edited.
A new parameter is added to the users/me REST API route containing the post type name. This parameter is used to get the corresponding post type capabilities.
Capability checks have been updated accordingly into Gutenberg editor components

Although cover-image block says "Drag image here or insert from media library", drag & drop upload was missing.

…s menu

We can remove a lot of code by subclassing WP_REST_Posts_Controller,
which gives us methods for creating, reading, updating and deleting
posts (in this case, blocks) for free.

This also adds support for DELETEing a block to the API, and renames the
'name' field to 'title'.

Also, add placeholder to HTML block.

Fixes #2249

…block

…forms

Add transforms between Heading & Cover Image

Add editor heading for screenreaders

…tter

Add tests for Editable.adaptFormatter()

This is a private method, that will probably need to be reevaluated in how we test it.

Add tests for Editable.getSettings()

This is a private method and the testing method may need to be reevaluated in the future.