Consolodate legal pages in new /about/legal hub
Bug 997577
Redesign Firefox Sync page for Bug 1046251
- Conditional contents depending on browser type/version
- New content/design only applies to en-US until other locales opt-in
Merge branch 'bug-1046251-sync-updates' into demo2-bug-997577-legal-notices-and-bug-1046251-sync-updates