dla-needed: reclaim packages, update notes

I am still working on faad2 and hdf5, still waiting for answers from
upstream in both cases.

My work on libsdl-image made progress, uploads will happen once I've
finished testing them.

I am still investigating issues in libsdl.

Not sure why pound is still in dla-needed since the only issue was
marked no-dsa in jessie. Planning to take a look.