Remove V8 submodule from QtDeclarative

Remove V8 submodule from QtDeclarative

QtDeclarative should now link against the QtV8 library
from qtbase.

The patch files have been moved to qtbase as well.

Applications that use the QtDeclarative private headers
may need to add the following to their .pro file:

QT += v8-private

This ensures that <private/v8.h> is found, which is
(indirectly) included by many QtDeclarative private
headers.

Task-number: QTBUG-20963

Change-Id: I31e973a6fcc0c416d3b258a61c26564cee3dcd4b
Reviewed-on: http://codereview.qt.nokia.com/3093
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>