This macro creates a movie from a sequence of images. The first argument
is the type of the movie~: it should be one of 
\verb+{Cmovie,Fmovie,Ccmovie,Cfmovie}+. The others 3 arguments describe
the image sequence, given by \verb+prefix_+$i$, where $i$ goes
from \verb+n1+ to \verb+n2+ included.