[S05-mass/properties-script] Bidi, lookahead
[S05-mass/properties-script] Bidi, lookahead

Restores the negative lookahead tests that were removed in f199800d;
updates Bidi_Class checks to use valued property syntax; adds missing
underscores to Old_Italic and Canadian_Aboriginal.

skids/roast,laben/roast,bitrauser/roast,niner/roast,zostay/roast,dankogai/roast,skids/roast,zostay/roast,niner/roast,dogbert17/roast,cygx/roast,laben/roast,b2gills/roast,zostay/roast,cygx/roast,b2gills/roast,dankogai/roast,skids/roast,niner/roast,perl6/roast,laben/roast,cygx/roast,bitrauser/roast,dogbert17/roast,dankogai/roast,b2gills/roast