LUDOC-69 failover: Updated failover documentation globally across 6 chapters.

LUDOC-69 failover: Updated failover documentation globally across 6 chapters.

Ch 3 Intro to Failover - edits for clarity, fixed missing figure
Ch 11 Configuring Lustre Failover - major rewrite to update and
clarify content
Ch 13 Lustre Operations - edited failover-related entries for clarity,
updated example from Elan to Ethernet, added cross-ref to Ch 11
Ch 14 Lustre Maintenance  - edited failover-related entries for clarity,
added crossref to Ch 11
Ch 20 MMP - changed chapter name from "Managing Failover" to
"Lustre Failover and Multi-Mount Protection", minor edits, added xref to Ch 11
Ch 36 - updated --servicenode and --failnode descriptons for mkfs.lustre
and tunefs.lustre
Changes to address Intel trademark compliance have also been made in these
chapters.

Signed-off-by: Linda Bebernes <linda.bebernes@intel.com>
Change-Id: I6f9b9f0b84d01e4d590c290dbc30738f5a0688cd
Reviewed-on: http://review.whamcloud.com/8058
Tested-by: Hudson
Reviewed-by: Richard Henwood <richard.henwood@intel.com>