* Rename DictionaryWorker => DictionaryWorkerHandler * Rename var * Rename file * Simplify * Rename DictionaryDatabaseModifier => DictionaryWorker * Rename dictionary-database-modifier.js => dictionary-worker.js
* Rename dictionary worker files * Rename classes * Rename file * Rename class * Generalize the _invoke method * Rename 'import' to 'importDictionary' * Improve DictionaryImporterMediaLoader usage * Refactor message handler * Generalize onProgress event