jens-benchmark/server: Improve benchmark.sh script
jens-benchmark/server: Improve benchmark.sh script

Delete (obsolte) restarting of servers from the script. Add cleanup after inter-
rupts and better size handling. Keep the size of the basefiles constant over
multi-thread benchmarks.

jswrenn/xtreemfs,kleingeist/xtreemfs,stanik137/xtreemfs,stanik137/xtreemfs,harnesscloud/xtreemfs,kleingeist/xtreemfs,rbaerzib/xtreemfs,jswrenn/xtreemfs,rbaerzib/xtreemfs,stanik137/xtreemfs,harnesscloud/xtreemfs,jswrenn/xtreemfs,rbaerzib/xtreemfs,kleingeist/xtreemfs,rbaerzib/xtreemfs,harnesscloud/xtreemfs,harnesscloud/xtreemfs,harnesscloud/xtreemfs,harnesscloud/xtreemfs,kleingeist/xtreemfs,rbaerzib/xtreemfs,kleingeist/xtreemfs,jswrenn/xtreemfs,kleingeist/xtreemfs,kleingeist/xtreemfs,jswrenn/xtreemfs,rbaerzib/xtreemfs,stanik137/xtreemfs,rbaerzib/xtreemfs,rbaerzib/xtreemfs,stanik137/xtreemfs,stanik137/xtreemfs,kleingeist/xtreemfs,harnesscloud/xtreemfs,jswrenn/xtreemfs,jswrenn/xtreemfs,jswrenn/xtreemfs,stanik137/xtreemfs,stanik137/xtreemfs,harnesscloud/xtreemfs