Jenkins core: Switching development server from jetty:run to hpi:run

[Tim Jacomb]

Hi all,

For anyone developing on Jenkins core we'll soon be switching from `mvn jetty:run` to `mvn hpi:run` when you want a development server.

It will run in a forked process so won't inherit the maven classloader which caused the odd issue with conflicts.

It will be a more production-like setup as it uses winstone which will inherit any jetty configuration done in winstone without us having to duplicate it.

See:

https://github.com/jenkinsci/jenkins/pull/27239

Thanks

Tim