* ColorTextField, helper methods, and regex for validating and handling text input

* Refactored structure to avoid creating new component for validation

* Style to adapt to error indicator

* Tests for validating input in ColorPickerPreview component's TextField

* Merge branch 'master' into colorpicker_validation

* Fix path to server class

* Fix test: Submit the new value

* Fix test: ignore Phantom JS

* Fix hsl+hsla validation patterns to accept '%', test value tweaking

* Merge branch 'master' of github.com:vaadin/framework into colorpicker_validation

* Fix: remove warning when color is updated from elsewhere

* Revisions: input validation only once, Logging level WARN

* Revisions: unit tests for color pattern matching

* Revisions: moved parsing to utility class, tests for parsing all accepted input formats

* Fixed import in tests, comments

* Revisions: Logger as constant, ignore utility class in serialization test

* Corner case tests

* Revisions: protected method for parsing error text, fix to test

* Revisions: NPE fix

Also improve naming by replacing one-letter variable names.

Also use "event" as the name for events

* Variable names to conform to naming convention.

* Use static constants where it makes sense

* Use .toLowerCase and .toUpperCase(Locale.ROOT)

* Spaces

* add spaces after if(

Also includes minor other javadoc and formatting fixes.

This patch provides a simple fix for the majority of issues. There are still issues that should be fixes by refactoring parts of the logic in AbstractSingleSelect.

This patch does not unify the handling of empty values in the TestBench elements of various AbstractSingleSelects.

Fixes #9494

Fixes #9550

Reset HDC when encountering unexpected changes in the data.

Additionally this patch fixes an issue with client and server caches
getting out of sync during resets.

Fixes #9241

Removes background color from Tree, adds release notes mention, JavaDoc updates.

* Use correct TreeElement and server-side classname
* Re-enable test, remove unnecessary imports

This patch introduces a Tree component, implemented as a Composite
using TreeGrid. As initial version of the component, some functionality
of the old Tree component has been left out for now.

Partly addresses #8617

Fixes #8943

Fixes #8846

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

Fixes #8611, Fixes #8620

* 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

* Reduce ComboBox initial requests

Use initial fetched data on client side,
do not request data from server side for each time popup is opened.
Fixed initial filter being null for ComboBox on DataProvider,
causing unnecessary size & fetch for not-changed filter.
Fixed ComboBox sending default filter unnecessarily to server.
Fixed wrong page indexing in VComboBox -> ComboBoxConnector.

Fixes #8496
Fixes vaadin/framework8-issues#488

* Fix last item missing

When pageLength was 0 and nullSelectionAllowed,
the last item was not shown. Tried to sensify the API
for total suggestions versus total suggestions + null selection item.

* Fix ComboBox selected item updates

Handles changing of ItemCaptionGenerator or ItemIconGenerator,
need to update the selected item caption and icon separately.
Previously it worked because all data was sent all the time to client.
Doesn't fix the issue, when selected item is updated with refreshItem(),
and it is not on the active range that will be sent to client.
For that, ComboBox would need a separate notification about item update.

* Updated screenshots

Now, only vaadin.testbench.version needs to be set for root and BOM
modules, and other modules do not need changes to upgrade TestBench.