Fixes warnings from rust-lang/rust#44229 when `--enable-commonmark` is
passed to rustdoc.
This is mostly a global find-and-replace for bare URIs on lines by
themselves in doc comments.
Fix FileAPI's refcount implementation
Revise several intricate parts of FileAPI's internal refcounting-related implementation.
Goal: Get it done right once and for all.
r? @Manishearth
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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
