[boost] Index.html for 1.31.0 and spirit

Is the index.html complete for 1.31.0? I think something could be mentioned for spirit as to what version it is now, and also the fact that it nolonger supports bcc32 compilers just to give people a warning that they are best to stick with 1.30.2 if they use spirit and borland compilers. (Or replace the spirit directory with the one from 1.30.2) Cheers Russell