FUNCTION: LieTools/SgNormalize
USAGE: SgNormalize(gpoly)
SYNOPSIS: SgNormalize(gpoly) normalizes an element gpoly in S[g]
  so that the leading term has coefficient 1
EXAMPLE: 
> x := 96*g[3]*g[2]^3+216*g[2]^2*g[3]^2+81*g[1]^4+16*g[2]^4+81*g[3]^4+216*g[2]*g[1]^2;

                   3           2     2          4          4
  x := 96 g[3] g[2]  + 216 g[2]  g[3]  + 81 g[1]  + 16 g[2]

                  4                2
         + 81 g[3]  + 216 g[2] g[1]

> SgNormalize(x);

  32          3           2     2       4   16     4       4
  -- g[3] g[2]  + 8/3 g[2]  g[3]  + g[1]  + -- g[2]  + g[3]
  27                                        81

                        2
         + 8/3 g[2] g[1]

SEE ALSO: LieTools[SgLeadingTerm]
