- add `[svn] eol_style` option
- add `Node.get_processed_content()`
- show substituted content in file viewer
- show differences between raw contents of two revisions in diff viewer
- store substituted contents using `svn:keywords` and `CRLF` for `svn:eol-style` in zip file
- use `Transfer-Encoding: chunked` for response of substituted content if both server and client support `HTTP/1.1`
- otherwise, use `Connection: close` instead
Closes #717.