* lib/msvfw32.def: New file.
* lib/avicap32.def: New file.
* lib/avifil32.def: New file.
* lib/vfw32.mri: New file.
* Makefile.in: (MRI_FILES, MIMPLIBS): New vars for
import libs with multiple dll's.
(LIBS): Add MIMPLIBS.
(DISTFILES): Add MRI_FILES.
(libvfw32.a): Build using mri script.
