Replace OpenStack LLC with OpenStack Foundation

Some files still use trademark OpenStack LLC in header, which
should be changed to OpenStack Foundation.

Change-Id: I6ab820e61514c6004247d9b931976e03baf84ae0
Fixes-Bug: #1214176
Fix broken links

Fix broken links on the system architecture page.

Change-Id: I7bffd18f629e076c8dc0372789bac9d765ee1ec0
Merge "Fix broken links"
Merge "Replace OpenStack LLC with OpenStack Foundation"