Webscrapbook

* Fixed a potential issue of bad directory moving.
* Miscellaneous optimization and refactoring of the source code and the unittest suite.

* Improved handling of boolean options for CLI.
* Improved the output of some CLI commands.
* Static site pages now are generated using the config locale if not otherwise specified.
* JavaScript files now use `text/javascript` as MIME type.
* Fixed a potential backup error in certain rare cases.
* Fixed the output format for server sent events when an unexpected error occurred.
* Fixed and improved some documentation.
* Miscellaneous optimization and refactoring of the source code and the unittest suite.

* Fixed and updated the search page:
* Fixed outdated browser support information.
* `create:` and `modify:` conditions are now "or"-connected.
* `book:` conditions are now matched by book ID.
* Search results are now shown in the order of provided `book:` conditions.
* A bad input for `sort:` and `limit:` is now forbidden.
* Fixed bad response for a user without read permission when visiting with an unknown action.

* Fixed an issue that removing an item may get an error when the recycle bin is empty.

* Fixed a packaging error causing a missing subpackage.

* Fixed a web interface issue that moved or copied files are misplaced if the target directory has a subdirectory with same name.
* Fixed an issue that downoloading a collection in a ZIP may get a bad filename.
* Fixed an issue that a file or directory can be unrestrictedly created at a subpath of a file in a ZIP.
* Fixed an issue that a directory can be unrestrictedly moved to a path under self and causes a further error in some cases.
* Fixed an issue that permissions are not preserved when copying a directory into a ZIP.
* Fixed an issue that metadata are not preserved when modifying a file in a ZIP.
* A directory entry is now generated at the target if there is no explicit directory entry when creating a directory in a ZIP.
* Locale now defaults to "en" if not defined, to prevent an issue of using a deprecated API.
* Fixed a packaging issue causing unusable test files be included in a source distribution.
* Improved packinging configs and scripts.
* Miscellaneous API error fix, documentation improvement, and code optimization and refactoring.