Webscrapbook

* Tab title is now taken when capturing a tab with `source` or `bookmark` mode.
* Added support of switching container for a capture in Firefox.
* Capturing a tab in a different container in Firefox is now disallowed to prevent an inconsistency.
* Miscellaneous improvements and fixes of the UI, internal code, and unit test suite.

* Fixed inconsistencies in recapture or merge-capture results when using certain capture helper options.
* Miscellaneous improvements of the internal code and test suite.

* Added `options` capture helper property, allowing for more reliable options overwriting, replacing the `options` command.
* Allow setting comment and merge capture in the details dialog when performing a capture with multiple pages.
* No longer download a linked file if the HTTP request fails when `capture.downLink.file.mode` is `header` for a capture.
* No longer fetch title and favicon for an attachment file when capturing a bookmark.
* The main document of a merge capture is now captured and updated even if a captured version already exists.
* No longer generate a redirect page for a merge capture on a file.
* Fixed an issue where the `index.html` page is incorrectly overwritten when capturing a deep XHTML/SVG page.
* Fixed an issue where an extra `index.json` is saved when capturing a file with depth set.
* Fixed incorrect site favicon path for a page that meta-refreshes to another page when capturing bookmark.
* Fixed incorrect saving path when the item directory path contains "%" for a merge capture.
* Fixed an issue where a link resolving to a page that redirects to a page with a captured version was not rewritten in the newly captured page of a merge capture.
* Fixed an issue where `capture.downLink.urlExtra` is applied for a merge capture without depth set.
* Fixed file renaming for the `application/ogg` MIME type in some older browsers.
* Miscellaneous improvements of the UI, internal code, and unit test suite.

* The expanded/collapsed status of option groups in the capture detail dialog now persists.
* Fixed a CSS handling error for certain `url()` when capturing a page.
* Fixed an error on certain invalid custom element names when capturing a page.

* Fixed script error when performing a merge capture on a file.
* Miscellaneous improvements of the UI and unit test suite.

* Added suppport of preserving manually assigned slots.
* Fixed an issue that capture selection does not work when the current selection is in a shadow DOM for Chromium.
* Fixed an issue that the current presentation of a canvas with non-2D context cannot be captured correctly.
* Fixed an issue that `Revert all erases` may cause a crash of the web page.
* Fixed an issue that some annotation tools work incorrectly inside a shadow DOM.
* Fixed an issue that the status of some form elements in the erased content is not appropriately reverted when the page is resaved and reopened.
* Fixed an issue that shadow DOMs and constructed stylesheets in the erased content cannot be reverted when the page is resaved and reopened.
* Miscellaneous improvements and fixes of the UI, internal code, and unit test suite.