editor 7.x-1.3

Changes since 7.x-1.2:

• Specifying validation and submission callbacks for an editor should be optional.
• Dialog pages should not be available for text formats with non-existent editors.
• Attachments should not be retrieved for non-existent text formats.
• Fixed the editor link dialog page title.
• Synced editor tests with core equivalents.
• The Llama test editor doesn't properly indicate that it supports configuration.
• The language plugin should be enabled by default.
• Submitting the filter format configuration page with a new editor and JavaScript disabled doesn't properly trigger a validation error indicating that the editor must be configured first.
• #3481298: Switching editor does not clear editor settings
• #3481297: Add CKEditor administration tests
• #3481295: Attemping to embed a file with an unknown file type results in a PHP error