Const-ify this arc4 interface.
Const-ify this arc4 interface.

Header changes which were omitted in the original patch.

darcs-hash:20081125201057-cac71-b5fbb87e42de11162a1e11af2727939ba93feab3.gz

nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf