First of all, thanks for a neat crate. I've just noticed there is wrong docs for the newly added Display-related functions:

    /// Format using SI (decimal) units.    
    pub fn iec_short(mut self) -> Self {

I think this should be: Format using a short style and IEC (binary) units.

    /// Format using a short style and IEC (binary) units.
    pub fn si(mut self) -> Self {

Should be: Format using SI (decimal) units.