tests: starting point for stress testing

This starting point for stress testing. Generates 200 files each
with 10000 random access rules. Does not yet support modify rules.
Next step would be probably making this more parametrized.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
chsmack: Major improvements

- Option -L (--dereference) added to dereference symbolic links
- Option -d (--remove) added to remove labels
- Validation of the labels
- Check that -t (--transmute) is applied on directories
- Use of names defined in <linux/xattr.h>
- Documentation updated

Change-Id: I83bd820b8f486df221a3f9e02dc7fd96b64c3f3f
Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>