CKEDITOR.filter should expose a way to bind standalone instance with editor to prevent memory leaks

[jacekbogdanski]

Type of report

Feature request

Provide description of the new feature

Currently, standalone CKEDITOR.filter instance cannot be removed during destroying editor because it doesn't contain a reference to the editor itself. We should add an optional way to bind filter and editor. Because of the polymorphic constructor, this request is pretty tricky, although we could move rules to the second constructor position as an optional parameter:

new CKEDITOR.filter( editorOrRules, [rules] )