scide: link with librt

fixes #816

Signed-off-by: Tim Blechmann <tim@klingt.org>
(cherry picked from commit 5e9de45ff77446837318d3c3b91aa14162c34e68)
supernova: CMakeLists.txt must set include dirs for fftw3f

Signed-off-by: Tim Blechmann <tim@klingt.org>
(cherry picked from commit c7eee2c1c31f7feee30fcf2d0f4903fc1c396c95)