Cocoa: create QCocoaMimeTypes for Cocoa-only mime-types

Prepare to move qmacmime out of the cocoa port and into
QPlatformSupport for sharing with iOS. This patch will
start by moving tiff out, since it depends too much on
old carbon image manipulation code that will not compile
on iOS (depends on ApplicationServices etc).

Change-Id: Id7a9b919c8f51fa9beb2f4ee2f13cca96894f6a6
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Cocoa: remove qmacmime includes where not needed

Change-Id: Id20df8b80f3064ac0d193124fb790a075a89e53c
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Cocoa: remove old carbon code from qmacmime

Prepare qmacmime to be moved to platform support by
removing unused includes and function declarations and
other dependencies on carbon or cocoa.

Also remove unneeded QCFString convertions, and use
UTI strings directly (fetched from apple docs) rather
than querying the system.

Change-Id: I8f622664c13f3fd05862720c3658cfc1b59baf28
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Cocoa/Platformsupport: move qmacmime from cocoa to platformsupport

Share qmacmime with iOS

Change-Id: Ied1b6ed74f2d63ef34d818554827a6165651b6a1
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>
qmacmime: bugfix unicode::canConvert

The UnicodeText converter is a bit special since it can convert
to both utf8 and utf16 for text/plain. But since flavorFor("text/plain")
can only return one UTI, it returns utf16. And this means that
canConvert will return false if given utf8 as argument.
On iOS this is often the only format available on the pasteboard, which
means that pasting text from another app app will fail.

This patch will ensure that it returns true for both utf8 and
utf16.

Change-Id: I31697f1815c19113393a8ef48f2ead4d7f1078ec
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>
iOS: implement clipboard

This will implement support for copy/paste operations
inside, and between, applications.

Change-Id: I50031b89bdb07f106950dc90fb8b1accbd1191bb
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@digia.com>