TT-59 remove . and - from the node name

TT-59 remove . and - from the node name

Replace . and - with _ in the node name, so it can be identified
as a variable in bash.

Change-Id: I0ae9c8225f9181a5b374fdb3c6316e47f2569ef1
Signed-off-by: sarah <sarah@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/376
Reviewed-by: Lai Siyao <laisiyao@whamcloud.com>
Reviewed-by: Chris Gearing <chris@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>