[clusterd] lsof takes ages and runs into timeout when proc are heavily using threads

[wwwutz]

Not really a clusterd issue, but since it uses lsof we need some sort of fix.

root:elcattivo:~/# time lsof | wc
2230392 26556082 487947192

real    1m53.222s
user    0m40.470s
sys     1m24.956s

To speed things up suggested fix: add -b -w

       -b       causes lsof to avoid kernel functions that might block - lstat(2), readlink(2), and stat(2).

Since in 99% of all cases we are only looking for open filenames, this might speed up a lot.

root:elcattivo:~/# time lsof -b -w | wc
2190884 20053174 341239540

real    0m33.197s
user    0m21.109s
sys     0m16.948s

[donald]

Fixed by #83