Filter for displaying jobs in Built-In HTML GUI

1. A new function 'Adminstrate filters' will be added to the Job Scheduler menu, which opens the filter administration in a new window. Inside the filter administration you can add new filters or edit and remove existing filters. Per filter a list of visible jobs will be shown. A checkbox beside every job can be used to add the respective job to the filter. The filters will be stored in a cookie.

2. A selectbox of filters will be shown in the Jobs tab, that restricts the job list to jobs that are contained in the selected filter. The name of the current filter will be stored in a cookie.