Automatic removal of old files in /work on fimm

/work on fimm now has automatic removal (delete) of files when usage is over 80% for the filesystem. The script similar to that on tre: it deletes files older than 21 days, then older than 14 days and so on... untill usage is below 80%. Do NOT touch your files to keep it new, it will only cause the filesystem to go 100% full and jobs to crash. /work2 will be added to the script later.