#o and unsignedness

[RWK at MIT-MC (Robert W. Kerns)]

Indeed, I never suggested that it should truncate.  I gave it a bit pattern
that would fit in a FIXNUM and it didn't fit it in a fixnum.  But on reflection
I think my other proposal is superior:  Replacing #*nnnn with #*O (or #*X or
#*D or #nn*R ...) to be unsigned.  There's even mnemonic value in the * being
neither - nor +.  This could even be made compatible with it's current
behaviour in that I don't know of any non-octal uses, so #*nnn could be the
same as #*Onnnn