Little CMS wrapper for Rust

Convert and apply color profiles with a safe abstraction layer for the LCMS library.

```rust extern crate rgb; extern crate lcms2; use lcms2::*;

fn main() {
    let icc_file = include_bytes!("custom_profile.icc");
    let custom_profile = Profile::new_icc(icc_file).unwrap();

    let srgb_profile = Profile::new_srgb();

    let t = Transform::new(&custom_profile, PixelFormat::RGB_8, &srgb_profile, PixelFormat::RGB_8, Intent::Perceptual);

    // Pixel struct must have layout compatible with PixelFormat specified in new()
    let source_pixels: &[rgb::RGB<u8>] = …;
    t.transform_pixels(source_pixels, destination_pixels);

    // If input and output pixel formats are the same, you can overwrite them instead of copying
    t.transform_in_place(source_and_dest_pixels);
}

```

See examples dir and LCMS2 documentation PDF for more info.

To apply ICC profile in JPEG:

rust if "ICC_PROFILE\0".as_bytes() == &app2_marker_data[0..12] { let icc = &app2_marker_data[14..]; // Lazy assumption that the profile is smaller than 64KB let profile = Profile::new_icc(icc).unwrap(); let t = Transform::new(&profile, PixelFormat::RGB_8, &Profile::new_srgb(), PixelFormat::RGB_8, Intent::Perceptual); t.transform_in_place(&mut rgb); }