ocfs2: Update default cluster timeouts

Lots of people are having trouble with the default timeouts, which are too
low. These new values are derived from an informal survey taken on
ocfs2-users, as well as data from bug reports. This should reduce the amount
of cluster disconnects and subsequent fencing seen during normal workloads.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>