Webscrapbook

* Added a capture helper command: `isolate`.
* Fixed incorrect title for `Capture frame as`.
* Improved the GUI of the target item selector for `Capture as` dialog.
* Added a rule filler for in-depth capture for `Capture as` dialog.
* No more include URLs with non-http(s) protocol for batch capture.
* Fixed an issue that the item picker for `Capture as` dialog incorrectly allows multi-selection through holding Shift.
* Various minor bug fixes and UI improvements.

* Fixed several GUI issues for the `Capture as` dialog for a multi-item capture.

* Fixed an issue that `Capture again` does not work correctly if `Save captured data to` is not `Backend server`.
* Added a link for the backuped page for re-capture if available. (Requires server >= 0.46)

* Added support of `mime:` prefix to filter linked files by MIME type.
* Fixed an issue that a linked file with no Content-Type header is not correctly handled by the file type filter.
* Fixed an issue that a reloaded iframe has inconsistent editor status with the main frame.

* A linked web page is no more downloaded as a resource file if `Depth to capture linked pages` is set.
* A linked attachment web page is now correctly treated as a resource file.
* Added `Extra URLs` option for the capture dialog.
* Fixed an issue that size limit does not work for a linked page with depth 1.
* Fixed an issue of capturing unexpected linked pages in a frame whose source is data protocol.
* Fixed an issue that a link in an extension tab cannot be opened in some browsers.

* Improved GUI for the `Capture as` dialog.
* A configured option whose value is same as default now updates with the app.