client:

- Changed default options to retry_delay = 15 seconds and number of attempts to 40 resulting in a maximum time a request might be pending between 10 minutes (15 seconds delay * 40 tries) and 40 minutes (60 seconds abort after connection or request timeout * 40 tries).
- Disable the interrupt signal for MacFuse.
- Enable always user_xattr(s) for MacFuse.
- Enable infinite retries for MacFuse as it seems to allow the interruption of requests.

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@2541 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534