Fix some deprecation warnings

* Update to new range/slice syntax
* `Show` renamed to `Debug`

src/buffer.rs

@@ -334,9 +334,7 @@ where Container: ArrayLike<T>, T: Primitive + 'static, PixelType: Pixel<T> + 'st
         let index  = no_channels * (y * self.width + x) as usize;
         Pixel::from_slice(
             None::<&PixelType>,
-            self.data.as_slice().slice(
-                index, index + no_channels
-            )
+            &self.data.as_slice()[index .. index + no_channels]
         )
     }
 
@@ -350,9 +348,7 @@ where Container: ArrayLike<T>, T: Primitive + 'static, PixelType: Pixel<T> + 'st
         let index  = no_channels * (y * self.width + x) as usize;
         Pixel::from_slice_mut(
             None::<&PixelType>,
-            self.data.as_mut_slice().slice_mut(
-                index, index + no_channels
-            )
+            &mut self.data.as_mut_slice()[index .. index + no_channels]
         )
     }
 
@@ -511,7 +507,7 @@ impl GreyImage {
         // Aquire a second view into the buffer
         let indicies = unsafe {
             let view: &mut [u8] = mem::transmute_copy(&data.as_mut_slice());
-            view.slice_to(entries)
+            &view[.. entries]
         };
         let mut buffer = ImageBuffer::from_vec(width, height, data).unwrap();
         for (pixel, &idx) in buffer.pixels_mut().rev().zip(indicies.iter().rev()) {

src/tiff/decoder.rs

@@ -401,7 +401,7 @@ impl<R: Reader + Seek> TIFFDecoder<R> {
                 try!(reader.read(&mut buffer[..length as usize]))
             }
             (color::ColorType::RGB(8), DecodingBuffer::U8(ref mut buffer)) => {
-                try!(reader.read(buffer.slice_to_mut(length as usize)))
+                try!(reader.read(&mut buffer[..length as usize]))
             }
             (type_, _) => return Err(::image::ImageError::UnsupportedError(format!(
                 "Color type {:?} is unsupported", type_

src/tiff/ifd.rs

@@ -95,7 +95,7 @@ pub struct Entry {
     offset: [u8; 4],
 }
 
-impl ::std::fmt::Show for Entry {
+impl ::std::fmt::Debug for Entry {
     fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
         fmt.write_str(&format!("Entry {{ type_: {:?}, count: {:?}, offset: {:?} }}",
             self.type_,