Merge branch 'v4-dev' of https://github.com/twbs/bootstrap into v4-dev

docs/4.0/components/forms.md

@@ -1018,6 +1018,46 @@ Custom `<select>` menus need only a custom class, `.custom-select` to trigger th
 </select>
 {% endexample %}
 
+You may also choose from small and large custom selects to match our similarly sized text inputs.
+
+{% example html %}
+<select class="custom-select custom-select-lg">
+  <option selected>Open this select menu</option>
+  <option value="1">One</option>
+  <option value="2">Two</option>
+  <option value="3">Three</option>
+</select>
+
+<select class="custom-select custom-select-sm">
+  <option selected>Open this select menu</option>
+  <option value="1">One</option>
+  <option value="2">Two</option>
+  <option value="3">Three</option>
+</select>
+{% endexample %}
+
+The `multiple` attribute is also supported:
+
+{% example html %}
+<select class="custom-select" multiple>
+  <option selected>Open this select menu</option>
+  <option value="1">One</option>
+  <option value="2">Two</option>
+  <option value="3">Three</option>
+</select>
+{% endexample %}
+
+As is the `size` attribute:
+
+{% example html %}
+<select class="custom-select" size="3">
+  <option selected>Open this select menu</option>
+  <option value="1">One</option>
+  <option value="2">Two</option>
+  <option value="3">Three</option>
+</select>
+{% endexample %}
+
 ### File browser
 
 The file input is the most gnarly of the bunch and require additional JavaScript if you'd like to hook them up with functional *Choose file...* and selected file name text.

docs/4.0/components/modal.md

@@ -210,7 +210,7 @@ When modals become too long for the user's viewport or device, they scroll indep
 
 ### Vertically centered
 
-Add `.modal-dialog-centered` to `.modal-dialog` to vertically center the modal. **Do not use this with long modals**—it will overflow the viewport and potentially hide parts of your modal.
+Add `.modal-dialog-centered` to `.modal-dialog` to vertically center the modal.
 
 <div id="exampleModalCenter" class="modal fade" tabindex="-1" role="dialog" aria-labelledby="exampleModalCenterTitle" aria-hidden="true">
   <div class="modal-dialog modal-dialog-centered" role="document">

docs/4.0/content/tables.md

@@ -586,7 +586,7 @@ Create responsive tables by adding `.table-responsive{-sm|-md|-lg|-xl}` to any `
 
 ## Captions
 
-A `<caption>` functions like a heading for a table. It helps users with screen readers to find a table and understand what it’s about and decide if they want to read it.
+A `<caption>` functions like a heading for a table. It helps users with screen readers to find a table and understand what it's about and decide if they want to read it.
 
 {% example html %}
 <table class="table">

docs/4.0/migration.md

@@ -11,6 +11,8 @@ toc: true
 While Beta 2 saw the bulk of our breaking changes during the beta phase, but we still have a few that needed to be addressed in the Beta 3 release. These changes apply if you're updating to Beta 3 from Beta 2 or any older version of Bootstrap.
 
 - Removed the unused `$thumbnail-transition` variable. We weren't transitioning anything, so it was just extra code.
+- Changed the CSS for managing multiple `background-image`s on custom form checkboxes and radios. Previously, the `.custom-control-indicator` element had the background color, gradient, and SVG icon. Customizing the background gradient meant replacing all of those every time you needed to change just one. Now, we have `.custom-control-indicator` for the fill and gradient and `.custom-control-indicator::before` handles the icon.
+- The npm package no longer includes any files other than our source and dist files; if you relied on them and were running our scripts via the `node_modules` folder, you should adapt your workflow.
 - Updated selector for input-based button groups. Instead of `[data-toggle="buttons"] { }` for style and behavior, we use the `data` attribute just for JS behaviors and rely on a new `.btn-group-toggle` class for styling.
 
 ## Beta 2 changes