Crop screen shots; improved xrefs in user guide

various user-guide images cropped

pre-install/4400-nodes-roles -- one tiny edit (don't to do not)

ref-arch/1100-ha-notes - added tag to reference from terminology/pacemaker

terminology
- p/pacemaker -- added links to CRM article and ref-arch material

user-guide/2000-deploy-new-environment
- xrefs between platform-services-ug and modify-services-ug
- xrefs between cinder-glance-backend-ug, assign-roles-ug, and settings-storage-ug
- Corrected commentary on the screens related to storage; LP1325151 is
  filed to create better docs about storage
- Deleted "Modify access permissions for Horzon" section -- it's a duplicate
- Deleted Syslog section.  The old docs didn't discuss it.  We have big logging
  features coming for 5.1 and will address Syslog in that context

Change-Id: Ia5992aa5ab98b0e7c8097a209ab1416f72d70906