Re-implement "Append Jenkins Build Number" option.

We are trying to upgrade from an old Hudson version to the latest Jenkins version and found that the "Append Build Number" option no longer exists in the m2release-plugin.

I see from JENKINS-20753 that this option was no longer functional and was removed from the UI.

I have re-implemented this feature, so that it does work which include the following improvements:

• includes the help originally requested in JENKINS-20753
• add a configurable "Pre-select" option

Apologies, this is my first experience with git and github and I'm not too sure what I'm doing. I used GitSVN to get a copy and make the changes. Then I created a fork on github and pushed them into that fork - here:

• https://github.com/niallkp/m2release-plugin

If you want to include this and there something I need to do to make it easier then please let me know.

Thanks