Enable the img_resample (old) code even if ffmpeg is built with libswscale
support. There were patches floating around for other OSes that did
something similar. While applications should be moving to libswscale,
some (e.g. vlc) haven't gotten there yet.
The ffmpeg developers moved part of avcodec.h into a new file allcodecs.h,
but have not modified the Makefile in libavcodec to install that header.
This broke dvbcut and possibly other ports that directly access decoder
or encoder functions (i.e. which do not use avcodec_find_decoder() to
search for them). Direct access to the functions has not been declared
deprecated (AFAIK) and thus it appears that installation of the header
has just been forgotten ...