Change per-tenant router use-case so tenant uplinks router

The per-tenant router use-case example implies that only the admin user is
is able to set the external gateway on the tenant's router. This is wrong
and this patch changes the example so the tenant does it instead.

Fixes bug: 1233167

Change-Id: Iec82581d3dad145be9d2327b9cf48b290a864f7a
Update GPFS Cinder Driver - improve readability

This commit has changes to GPFS cinder driver documentation to
improve readability and to re-add use of service names instead
of project names in the text.

Change-Id: I64615733b4b49cb198e508377d176d23fed4bc42
Fix broken URLs

This fixes a number of broken URLs in the guides.

Change-Id: Iae027614ec7466fefafa1b504b348f795bb5fac7
Partial-Bug: #1225093
Merge "Change per-tenant router use-case so tenant uplinks router"
Merge "Update GPFS Cinder Driver - improve readability"
Merge "Fix broken URLs"