Building with enhanced clang warnings indicated a large number of
instances with the warning:
`warning: zero as null pointer constant`
Recommended practice in C++11 is to use `nullptr` as value for
a NULL or empty pointer value. All instances where this warning
was encountered were corrected in this commit.
Where warning was encountered in dependency code (i.e. external library)
no chnages were made. Patching will be offered upstream.
We have now one list for checked platforms, menu items are created
dynamically based on that list. This makes it much easier to alter
the platforms list later on.
Daniel Marjamäki
Oliver Stöneberg
Paul Fultz II
Scott Furry
Lauri Nurmi
Jakub Melka
Reijo Tomperi
Daniel Marjamäki
Kimmo Varis