After trying to get rid of all private header includes, the last
standing one is qplatformnativeinterface.h even though its name
previously suggested that it isn't private.

This would be a complicated piece to expose publically in a way both
flexible and binary compatible, and is a task heavy enough to
justify committing to follow Qt's release cycle.

The QML import version remains to 1.0 and will be incremented the
same manner as QtQuick itself does.

Change-Id: I6fab5f229d9f79dbc7a3e82d65ad324020929863
Reviewed-by: Michael Bruning <michael.bruning@digia.com>