I had it in Jetty in 5 minutes, was able to configure it with a test Eclipse Client and was able to run it.
- Unsuccessfully, and the reason bacame apparent in the console immediately.
 The prerequisite

interface="com.ibm.team.workitem.service.IworkItemServer"

is wrong. It needs to be

interface="com.ibm.team.workitem.service.IWorkItemServer"

I fixed that and it did work.
I also went into the dependencies and found a dependency to the jazz component defined in the Extension Workshop, which I removed.

I then deleted all files and folders, except the site.xml file in the update site project and ran Build All again.
I created a project to ease deployment and copied the site.xml, the folders Features and Plugins into the update site folder I created:
 

I then copied the folders provision_profiles and sites from the Eclipse workspace and pasted it into the server/conf/ccm folder. I started the server and was able to configure, run and debug the extension.
I used https://rsjazz.wordpress.com/2014/06/12/is-the-extension-deployed-how-can-i-redeploy/ and deleted the built-on.txt file to enforce a redeployment once, because the first attempt had still a typo in the prerequisites and the extension did not run but failed with an exception that I was able to see in the server/logs/ccm.log.


So, as I see it, you have not tried your extension with Jetty in the first place.

I have seen this over and over and over again, if you don't set up your development environment with Jetty as explained in the links above and try to write something and deploy it on Tomcat for debugging, you will fail and complain on the Forum.

I did nothing really that was complex in any way or deviated from the descriptions in the Extensions Workshop. I read the error messages carefully and fixed the problems.
I only added this one serverdeploy project, because it helps to organize the required provision profile and makes deployment more reliable.

While you created your example, you must also have ignored a warning from Eclipse, because class names should start with a capital letter an your extension class does not.

In general, as mentioned in the links above, this is serious work. If you don't follow it carefully it gets unmanageable. If you want to rush this and go directly to Tomcat or WAS, all you create is uncertainty and problems.

Jetty helps to make sure the stuff would work at all and once that is clear, deployment problems are usually only related to Java Versions and false dependencies.