Modification to AskSage() to allows passing $problemSeed to SAGE's set_random_seed()

Also, sage blocks should ``print``the result of their computation. So, e.g.
```
Context("Matrix");
$python=<<END;
print random_matrix(QQ,4,5,algorithm='echelonizable',rank=3).rows()
END
$sage = AskSage($python,{seed=>$problemSeed});
$M = Matrix($sage);

$python2 =<<END;
print matrix(QQ,$sage).rref().rows()
END
$sage2 = AskSage($python2,{seed=>$problmeSeed});
$ans = Matrix($sage2);
Context()->texStrings;
BEGIN_TEXT

Row reduce \( $M \) $BR
\{ $ans->ans_array\}
END_TEXT
Context()->normalStrings;
ANS($ans->cmp());
```