The websocket JAR provided by Tomcat is not identified as a core extension

Right now, in Tomcat (and also probably other applications servers too), the websocket JAR provided by Tomcat is no identifier as a core extension. So if you try to install something which have a transitive dependency on websocket, it will try to install it and it could create a quite a mess.

Right now, it's not identified because:

• that JAR does not contain any Maven metadata
• it's not indicated as dependency by another JAR

We might be able to hack something with what we can find in META-INF/MANIFEST.MF, but it's hardly anything that looks like the expected standard javax.websocket:javax.websocket-api so we would need some mapping.