Annotated to be removed Tree API with @noreference and @noextend

See https://wiki.eclipse.org/Eclipse/API_Central/API_Removal_Process.

Bug: 486105
Change-Id: I460e43da0d487279608729a2081c614e7065f56f
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>

org.eclipse.jgit/src/org/eclipse/jgit/lib/FileTreeEntry.java

@@ -54,6 +54,8 @@ import java.io.IOException;
  * To lookup information about multiple paths at once, use a
  * {@link org.eclipse.jgit.treewalk.TreeWalk} and obtain the current entry's
  * information from its getter methods.
+ * @noreference This class is not intended to be referenced by clients.
+ * @noextend This class is not intended to be subclassed by clients.
  */
 @Deprecated
 public class FileTreeEntry extends TreeEntry {

org.eclipse.jgit/src/org/eclipse/jgit/lib/GitlinkTreeEntry.java

@@ -55,6 +55,8 @@ package org.eclipse.jgit.lib;
  * To lookup information about multiple paths at once, use a
  * {@link org.eclipse.jgit.treewalk.TreeWalk} and obtain the current entry's
  * information from its getter methods.
+ * @noreference This class is not intended to be referenced by clients.
+ * @noextend This class is not intended to be subclassed by clients.
  */
 @Deprecated
 public class GitlinkTreeEntry extends TreeEntry {

org.eclipse.jgit/src/org/eclipse/jgit/lib/SymlinkTreeEntry.java

@@ -54,6 +54,8 @@ package org.eclipse.jgit.lib;
  * To lookup information about multiple paths at once, use a
  * {@link org.eclipse.jgit.treewalk.TreeWalk} and obtain the current entry's
  * information from its getter methods.
+ * @noreference This class is not intended to be referenced by clients.
+ * @noextend This class is not intended to be subclassed by clients.
  */
 @Deprecated
 public class SymlinkTreeEntry extends TreeEntry {

org.eclipse.jgit/src/org/eclipse/jgit/lib/Tree.java

@@ -63,6 +63,8 @@ import org.eclipse.jgit.util.RawParseUtils;
  * To lookup information about multiple paths at once, use a
  * {@link org.eclipse.jgit.treewalk.TreeWalk} and obtain the current entry's
  * information from its getter methods.
+ * @noreference This class is not intended to be referenced by clients.
+ * @noextend This class is not intended to be subclassed by clients.
  */
 @Deprecated
 public class Tree extends TreeEntry {

org.eclipse.jgit/src/org/eclipse/jgit/lib/TreeEntry.java

@@ -56,6 +56,8 @@ import org.eclipse.jgit.util.RawParseUtils;
  * To lookup information about multiple paths at once, use a
  * {@link org.eclipse.jgit.treewalk.TreeWalk} and obtain the current entry's
  * information from its getter methods.
+ * @noreference This class is not intended to be referenced by clients.
+ * @noextend This class is not intended to be subclassed by clients.
  */
 @Deprecated
 public abstract class TreeEntry implements Comparable {