We don't need it since IO#read(bytes, buf) will convert to
ASCII-8BIT anyways. Everywhere else, we ensure path names are
already binary. We do this mainly at the client layer before using
Shellwords to escape the paths.
We also must be careful about parsing output from soxi/avprobe
which can show us metadata in whatever encoding is in the file.
We must still handle data from parsing command output as binary,
as the encoding of file metadata tends to vary.
This also should buy us Syck compatibility for Ruby 1.9.3 users
on Debian systems where Ruby 1.9.3 still uses Syck.