* 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

* Update since tags for 8.1.0.alpha2

JavaDoc now more explicitly states that hasChanges is not designed to work with setBean.

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

Fixes #8893

Fixes #8752

Closes #8795

Closes #8760

* Add missing since tags for 8.1.0.alpha1

* Update @since for DataCommunicatorClientRpc

* Update @since for DataCommunicator

Fixes #8416

Fixes #8629

Fixes #8800

* Initial HierarchicalDataProvider for TreeGrid
* Initial in-memory hierarchical data implementation
* TreeGrid declarative support

Fixes #8611, Fixes #8620

Closes #8250

* Fixes #8810, #8658

Fixes #8467

* Update frozen column count when a frozen column is removed

Fixes #8658

Emphasise that both location and filename for the design file can be specified in the value parameter.

* RichTextField unnecessarily overwrites clear method

Fixes #8801

Fixes #8734

* Correctly detach components in merged cells

This was already once fixed in 7.7 in #8142

Fixes #8622 
Fixes #8623

Fixes #8722

Fixes #8751

Synchronises parts of compatibility package code to match 7.7
Picks suitable patches for 8 code as well

Fixes #8704

To ensure the resource is automatically closed

* Add Column.getValueProvider to Grid

Fixes #8680

Fixes #8715

* Add @author and @since tags to drag and drop related new files (#8693)

* Allow powerful Navigator subclassing

`protected` methods in `Navigator` permit to create new `Navigator`s to add new capabilities to Vaadin, but `Navigator` fields are still `private` and this limit, for example, the overriding of `Navigator.init`. This PR makes `private` the `Navigator` fields.

* Add documentation blocks to protected fields

Partial fix for #8640

* Fix NPE sorting columns with null values

Sorting a column in Grid throws a NullPointerException if there are null values and we are using the default TextRenderer

* Test for #8610

* Update Grid.java

* Update GridNullValueSortTest.java

* Update GridNullValueSortTest.java

* Add initial implementation of TreeGrid

* Refactor TreeGrid and related classes

* Fix potential class cast exception in TreeGrid#getDataProvider

* Add smoke tests for TreeGrid

* Add communication constants for TreeGrid

Use shared constant values for hierarchy data serialization and deserialization

* Fix event ordering in TreeGrid, add javadocs, keyboard navigation test

* TreeGrid improvements

* Add TreeGrid.getDataProvider to StateGetDoesNotMarkDirtyTest exclude list

* Merge remote-tracking branch 'github/master' into tree-grid

* Remove getEscalator override from TreeGrid

* Make DragSource extension/component available in DropEvent (resolves #8439)

* Update drag and drop test to use new API

* Change type of drag source and update javadoc

* Use existing data map instead of DataTransfer

* Fix java packaging order (#106)

Closes vaadin/archetypes#113

* Use proper UTF-8 encoding for Content-Disposition filenames (#19527) (#6607)

* Enable changing the backing bean for BeanItem (#4302) (#77)

When storing a bean to the database, you typically get a new and updated
bean instance back. By allowing to change the bean instance, we make it
possible to just update the single BeanItem instance which can be used
in many places.

* Make AtmospherePushConnection methods public (#7973)

There is no sensible way to use a custom version of APC, so protected
access does not help in any way to access the underlying resource and/or
connected UI.

* Use correct indexes in multiselect checkboxes after removing rows (#8072)

Fixes #8011

* Fix removal of hidden Grid columns (#8071)

Fixes #8018

* Call error handler for exceptions in UI.init() (#8055)

Fixes #4995

* Render font icon correctly on the 'more' menu item (#8126)

* Render font icon correctly on the 'more' menu item

Fixes #8125

* Reopen Grid details on attach, fixes #8015 (#8074)

Fixes #8015

* Fix broken Grid tests after picking changes from 7.7.7

Removed duplicate setDetailsVisible calls from onDetach

* Correctly detach components in merged cells when a static row is removed (#8142)

Fixes #8140

* Load declarative classes using thread context class loader

Fixes #8528

* Add javadoc warning and example for criteria scripts (#8521)