Summary
------

Terminally deprecate (add  `forRemoval=true) the following JDK-specific APIs, these APIs have been deprecated since JDK 9.

```
com.sun.jarsigner.ContentSigner
ContentSignerParameters
```

Problem
------
The function was deprecated in JDK 9. Now it's time to mark them for removal.

Solution
------
Add the `forRemoval` argument to the related classes and update several `jarsigner` outputs.

Specification
------

    diff --git a/src/jdk.jartool/share/classes/com/sun/jarsigner/ContentSigner.java b/src/jdk.jartool/share/classes/com/sun/jarsigner/ContentSigner.java
    --- a/src/jdk.jartool/share/classes/com/sun/jarsigner/ContentSigner.java
    +++ b/src/jdk.jartool/share/classes/com/sun/jarsigner/ContentSigner.java
    @@ -38,7 +38,7 @@
      * @deprecated This class has been deprecated.
      */
    
    -@Deprecated(since="9")
    +@Deprecated(since="9", forRemoval=true)
     public abstract class ContentSigner {
    
         /**
    diff --git a/src/jdk.jartool/share/classes/com/sun/jarsigner/ContentSignerParameters.java b/src/jdk.jartool/share/classes/com/sun/jarsigner/ContentSignerParameters.java
    --- a/src/jdk.jartool/share/classes/com/sun/jarsigner/ContentSignerParameters.java
    +++ b/src/jdk.jartool/share/classes/com/sun/jarsigner/ContentSignerParameters.java
    @@ -36,7 +36,7 @@
      * @author Vincent Ryan
      * @deprecated This class has been deprecated.
      */
    -@Deprecated(since="9")
    +@Deprecated(since="9", forRemoval=true)
     public interface ContentSignerParameters {
    
         /**

    diff --git a/src/jdk.jartool/share/classes/com/sun/jarsigner/package-info.java b/src/jdk.jartool/share/classes/com/sun/jarsigner/package-info.java
    --- a/src/jdk.jartool/share/classes/com/sun/jarsigner/package-info.java
    +++ b/src/jdk.jartool/share/classes/com/sun/jarsigner/package-info.java
    @@ -30,9 +30,9 @@
      * tool by supplying an alternative implementation of
      * {@link com.sun.jarsigner.ContentSigner}.
      *
    - * The classes in this package have been deprecated. New classes should not be
    - * added to this package. Use the {@link jdk.security.jarsigner.JarSigner} API
    - * to sign JAR files.
    + * The classes in this package have been deprecated and will be removed in
    + * a future release. New classes should not be added to this package.
    + * Use the {@link jdk.security.jarsigner.JarSigner} API to sign JAR files.
      */
     
     package com.sun.jarsigner;

Also, update jarsigner to show the following messages on the help screen:

    $ jarsigner
    Usage: jarsigner [options] jar-file alias
           jarsigner -verify [options] jar-file [alias...]
    
    ....
    [-altsigner <class>]        class name of an alternative signing mechanism
                                (This option is deprecated and will be removed in a future release.)
    
    [-altsignerpath <pathlist>] location of an alternative signing mechanism
                                (This option is deprecated and will be removed in a future release.)
    ....

An updated warning will also be shown when an deprecated option is used:

    $ jarsigner -altsigner X
    This option is deprecated and will be removed in a future release: -altsigner