* Add API support for setting server side drag data

* Fix javadocs

* Add server side drag data API to ASCII doc

* Fix some javadocs and documentation details

Fixes #8846

* Use difference GUI component for Vaadin 8 

With Vaadin Framework 8, Tutorial learner should use different setting and component for form development

* Better explanation

* Remove API for setting arbitrary drag data
* Store the drag source component in the UI

Fixes #8893

Closes #8760

Fixes #8416

* Initial Documentation for TreeGrid and Hierarchical Data

Fixes #8615, part of #8616

* Initial documentation for 8.1 Drag and Drop

Part of #8395

Closes #8250

* components-grid to use correct function setHidable

The correct function to use in Vaadin 8 (also before) is setHidable()
https://vaadin.com/api/8.0.0/com/vaadin/ui/Grid.Column.html#setHidable-boolean-
For 7.7.7:
https://vaadin.com/api/7.7.7/com/vaadin/ui/Grid.Column.html#setHidable-boolean-

* Fix broken link

* Remove mentioning of removed example from progressbar docs

Fixes #8622 
Fixes #8623

* Updated tutorial: Use Grid::setColumns

* Updated tutorial: use Binder instead of BeanBinder

* Fixed tutorial (use parameterized Grid)

* Fixed tutorial (use parameterized Grid)

* Merge branch 'master' of https://github.com/alejandro-du/framework

* Fix documentation links

Deprecated setColumns was removed in fd3617b

* Updated tutorial: Use Grid::setColumns

* Updated tutorial: use Binder instead of BeanBinder

* Fix grid column sort order documentation

* Remove class names from documentation headers

* Updated migration related documentation

More detailed information on compatibility components.
Mention vaadin:upgrade8 target in migration guide.

Fixes #8581

organized was already fixed so added This.

Fixes #8522

This patch also provides a documentation for #8382.

Fixes #8390

* Add isValid to Binder

isValid enables you to check the current validation
status of a given Binder, without firing events or invoking
handlers.

This patch also clarifies the javadocs of StatusChangeEvents'
hasValidationErrors.

* Throw in Binder.isValid if no bean is set and bean validators exist

* Add test cases to BinderTest

* Add header required by docs site

* Include FontAwesome by default for easier migration
* Fix JSComponentLoadingIndicatorTest

Fixes #7979
Addresses part of #8219

* Make Grid add columns based on bean properties

The property set concept used for Binder is slightly generalized and
used by Grid as well to support similar functionality.

Fixes vaadin/framework8-issues#250

Fixes #8366

* Add DataProvider refreshItem for single item update

* Add 'id' concept for DataProviders

This patch also adds a simplified data provider that can replace items
based on their id. This can be used to simulate stale objects from an actual
backend.

* Add refresh logic to Grid SelectionModels

* Remove broken equals and hashCode

* Refresh KeyMapper, clean up some methods

* Fix UI.access in test

* Fix tests and Grid single selection model

* Do clean up before replacing data provider

* Check correct variable for null value

* Fix other selects, add generic tests

* Code style fixes, removed assert

* Merge remote-tracking branch 'origin/master' into 286_refresh_items

* Fix documentation for refreshing an item

* Improve introduction chapter, minor clarifications

* Merge remote-tracking branch 'origin/master' into 287_refresh_items

* Add missing parameters in unit tests

Note that not all browsers yet support HTML imports. If a polyfill
is needed to load HTML imports, it must be loaded before HTML Imports
can be loaded. There is no automatic loading of any polyfills.

* Allow distinct configurable filter and wrapped filter types

This enables implementing the use case that was already described
towards the end of datamodel-providers.asciidoc.

Also swaps the order of the callback type parameters to make all three
match the order of the ConfigurableFilterDataProvider type parameters.

* Migration guide 1st draft

* Restructure and improve migration guide

* Update migrating-to-vaadin8.asciidoc

* Change BackEndDataProvider into an interface

BackEndDataProvider is now an interface with methods for setting
sorting options based on SortOrder instances. 

AbstractBackEndDataProvider stores sorting options, combines them with
the sorting provided in the query and invokes its own abstract fetch and
size methods.

CallbackDataProvider implements a BackEndDataProvider based on two
lambdas.

This is one of many steps towards #8245

* Removed obsolete 'Setting up the Development Environment' link in tutorial'

* Avoid using Guava API in the documentation

* Integrate BeanBinder functionality into Binder

* Fix broken Grid documentation addColumn setHeaderCaption

Minor documentation fixes.