disable initial retrieval of job status

[jack-kerouac]

Sometimes, the jambel control is not able to connect to the Jenkins build server in order to retrieve the name of the jobs and their current status. As a consequence, every job that cannot be intially retrieved is removed.
Each job should have an option that indicates whether its status should be retrieved upon starting the jambel control. If the job status should not be retrieved, the name of the job (as provided by Jenkins) need to be provided in the configuration. Furthermore, a job status UNKNOWN need to be added and taken into account when aggregating the job states into a state being displayed with the signal light.