Fixed issue with missing quotes, added code to allow stand-alone testing

without being run from autotests.sh, now only considering tests with
format DD_NAME.sh (DD: 2 digits), added way to change number of OSDs and
STRIPE_WIDTH for testing, added comments, made temporary directories
more flexible and less hardcoded to the ZIB environment, such that a
standalone test can work anywhere, etc...

This script could have been easilly derived from the
basic_client_tests.sh instead of being written from scratch, but
well...


git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@33 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534