Don't overwrite the body if there are no changes.
Do not compare formatted output with body size if they do not differ in size.
Read the file reader and the body reader in chunks.
Do not compare the formatted output with the body if the sizes differ. We can assume a change and write the formatted output to the body.
Use functions instead of gotos.
Rewind body instead of reopening the window.
Rename sizeReader and sizeWriter to countReader and countWriter.
Use ReadByte instead of allocating one byte each time through the loop.
Cleanup naming.
Refactor handling of a formatting change.
Rewrite body even if bodyDiff returns an error.
Log bodyDiff error to os.Stderr.
Merge pull request #2 from davidrjenni/master

Don't overwrite the body if there are no changes.

Fixes #1.