Filed for GitHub pull request #172

Right now, the name of a slave needs to match the computer name when using the Windows service option in Jenkins.

This request adds a Host field to the Node config screen to allow you to specify a hostname that's different from the slave name if required. The computer name defaults to the slave name if host isn't specified.

This is my first pull request for core so let me know if there's anything that needs to be fixed up / added / etc.