bugfix, seq mode was using par mode 50% of time for RESIZ benchmark.

Also, as a drive-by convenience, made script infer `libdir` if it was
not provided.  It warns loudly when it does this to try to catch
mistakes.  The point is that now, if you like, you can run like so:

    % ../../../objdir-js/js -i liquid-resize.js
    Selecting default libdir of './';
    you should override if you are not running from current directory.
    js> tinyImage.timedShrinkBW(10, 5)
    ({topar:12, trans:0, edges:32, energ:0, fpath:1, cpath:1})
    js>
Merge branch 'master' of https://github.com/syg/iontrail