Revision 1651

         + removed the x_Ref%4 in qpel.h, in favor of x_Ref>>2.
        As suggested by Gruel, there might be a compiler
        problem for some very very exotic platform.
        Hence, i've added a test_compiler() in xvid_bench.c, to
        be sure everything are ok. Hope the test is correct.

        + added benches for interlaced decoding, as supplied
        by Christoph Kühnel (info at intek-darmstadt dot de).
        Thanks a lot.