[CB-3820] non-default preference values; light edits
[CB-3820] gather queries
[CB-3820] move PGB's icon/splash content to platform-specific config
[CB-3820] rewrite platform-specific icon/splash content
[CB-3820] rewrite global icon config content
[CB-3820] Using BB10 config page, vanilla BB config is minimal
unrelated: removed empty stub for firefoxOS config
[CB-3820] global icon/splash content; more queries; custom URLs in iOS
[CB-3820] new icon/splash content for WP
[CB-3820] link to WP icon/splash content
[CB-3820] conolidate new section for non-global, multiplatform prefs