Documentation cleanup (#612)

* Added the `@Deprecated` tag to instances where is was mentioned in documentation, but not for the actual code itself.

Changed one documentation link pointing at a non-existing item.

* As per PR suggestion.

imageio/imageio-metadata/src/main/java/com/twelvemonkeys/imageio/metadata/exif/EXIFReader.java

@@ -46,6 +46,7 @@ import java.io.IOException;
  *
  * @deprecated Use com.twelvemonkeys.imageio.metadata.tiff.TIFFReader instead.
  */
+@Deprecated
 public final class EXIFReader extends MetadataReader {
 
     private final TIFFReader delegate = new TIFFReader();

imageio/imageio-metadata/src/main/java/com/twelvemonkeys/imageio/metadata/exif/EXIFWriter.java

@@ -48,6 +48,7 @@ import java.util.Collection;
  *
  * @deprecated Use com.twelvemonkeys.imageio.metadata.tiff.TIFFWriter instead.
  */
+@Deprecated
 public final class EXIFWriter extends MetadataWriter {
 
     private final TIFFWriter delegate = new TIFFWriter();

imageio/imageio-metadata/src/main/java/com/twelvemonkeys/imageio/metadata/exif/Rational.java

@@ -41,6 +41,7 @@ package com.twelvemonkeys.imageio.metadata.exif;
  *
  * @deprecated Use com.twelvemonkeys.imageio.metadata.tiff.Rational instead.
  */
+@Deprecated
 public final class Rational extends Number implements Comparable<Rational> {
     private final com.twelvemonkeys.imageio.metadata.tiff.Rational delegate;
 

imageio/imageio-metadata/src/main/java/com/twelvemonkeys/imageio/metadata/exif/TIFF.java

@@ -39,5 +39,6 @@ package com.twelvemonkeys.imageio.metadata.exif;
  *
  * @deprecated Use com.twelvemonkeys.imageio.metadata.tiff.TIFF instead.
  */
+@Deprecated
 public interface TIFF extends com.twelvemonkeys.imageio.metadata.tiff.TIFF {
 }