RFR: 8303410: Remove ContentSigner APIs and jarsigner -altsigner and -altsignerpath options [v4]

[Wei-Jun Wang]

IIUC there is no place to add a reviewer's name. As long as you follow the steps in https://openjdk.org/guide/#release-notes, someone reviews it, and the state becomes Delivered, I think it's done.

Thanks,
Weijun

> On Apr 13, 2023, at 7:14 AM, Eirik Bjorsnos <duke at openjdk.org> wrote:
> 
> On Thu, 9 Mar 2023 18:50:42 GMT, Eirik Bjorsnos <duke at openjdk.org> wrote:
> 
>>> The `-altsigner` and `-altsignerpath` options in JarSigner with the underlying `ContentSigner` mechanism were deprected in Java 9, for removal in Java 15. See [JDK-8076535](https://bugs.openjdk.org/browse/JDK-8076535), [JDK-8242260](https://bugs.openjdk.org/browse/JDK-8242260).
>>> 
>>> This PR suggests it's time to remove this code:
>>> 
>>> - The package `com/sun/jarsigner` is removed. This contained the `ContentSigner` and `ContentSignerParameters` along with a `package-info.java` file.
>>> - `JarSigner.java` is updated to remove processing of the `-altsigner` and `-altsignerpath` options and the loading and processing of the custom `ContentSigner`.
>>> - Similarly `c.s.s.t.jarsigner.Main` is updated to remove processing and mentioning of `-altsigner` and `-altsignerpath` options.
>>> - Mentions of the options in Resource files in the same directory is removed
>>> - The `jarsigner.1` man page is updated to remove the section on the deprecated options
>>> - The `Spec` and `Options` tests are update to remove usage of the `-altsigner` and `-altsignerpath` options.
>> 
>> Eirik Bjorsnos has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>  Remove unused resource names 'This.option.is.forremoval' and 'using.an.alternative.signing.mechanism'
> 
> I see that the Release Note for this PR did not seem to get any review comments or edits. Probably it's ok, but perhaps a Reviewer could take an extra look anyway:
> 
> https://bugs.openjdk.org/browse/JDK-8303536
> 
> -------------
> 
> PR Comment: https://git.openjdk.org/jdk/pull/12791#issuecomment-1506780727