Added is_file member to Stdio.File. It's true if the file is a file and not a...

Added is_file member to Stdio.File. It's true if the file is a file and not a socket or a pipe. This is in turn used by Stdio.sendfile to avoid non-blocking I/O on files (since it does not make all that much sense, really, and it's slower than blocking I/O)

Rev: lib/modules/Stdio.pmod/module.pmod:1.91