tests: Added --{dir,mrc,osd}--suffix options to xstartserv to ease starting...

tests: Added --{dir,mrc,osd}--suffix options to xstartserv to ease starting multiple instances of the XtreemFS services with different log and pid files.

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@2517 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534