Minor branding update from Prizm Cloud to Prizm Viewer

git-svn-id: https://plugins.svn.wordpress.org/prizm-cloud-document-viewer/trunk@891479 b8457f37-d9ea-0310-8a92-e5e31aec5664
Changed a few more words in the readme

git-svn-id: https://plugins.svn.wordpress.org/prizm-cloud-document-viewer/trunk@891481 b8457f37-d9ea-0310-8a92-e5e31aec5664