1. More complete origin check in FileManagerThreadMsg
2. Add reference counting logic to file manage store and script API
3. Integrate the support of slicing
Changes include:
- Implement file selection and other DOM behaviours in htmlinputelement
- Integrate IpcSender<FileManagerThreadMsg> into ResourceThreads
- Improve filemanager_thread, including adding type_string field to SelectedFile
- Improve interfaces in FileList/File/Blob to accommodate the above changes