Use a *bytes.Buffer rather than an io.Writer internally
Use a *bytes.Buffer rather than an io.Writer internally

Since we're rendering to an intermediate buffer, we can just
avoid using the interface, which speeds up calls to Write()
and avoids type assertions in io.WriteString(). For big templates,
this increases performance by ~2%.

rainycape/gondola,rainycape/gondola,rainycape/gondola,rainycape/gondola