[CB-2411] Added CameraPopoverHandle documentation.
CB-2525: Correct docs for iOS splashscreen sizes

-correct to sizes from http://developer.apple.com/library/ios/#documentation/userexperience/conceptual/mobilehig/IconsImages/IconsImages.html
Updated iOS documentation for disallowOverscroll.
Updated docs for FileTransfer.download headers

As per issue CB-861, I have updated the docs for FileTransfer to list the optional headers
Clarification of "Basic authentication"
[CB-1687] Added Camera.Direction documentation.

Also, fixed spacing issues; couldn't resist.
[CB-2659] Added documentation for NATIVE_URI.
CB-2490 Describe NetworkConnection.type.CELL

- add CELL type
- updated examples
- updated WP7 / WP8 usage
- added deprecation note for iOS