code: function(symbol, factors) {
                  if(symbol.isComposite()) {
                      var gcd = core.Math2.QGCD.apply(null, symbol.coeffs());
                      if(!gcd.equals(1)) { 
                          symbol.each(function(x) {
                              if(x.isComposite()) {
                                  x.each(function(y){
                                      y.multiplier = y.multiplier.divide(gcd);
                                  });
                              }
                              else x.multiplier = x.multiplier.divide(gcd);
                          });
                      }
                      symbol.updateHash();
                      if(factors) 
                          factors.add(new Symbol(gcd));
                  }
                  return symbol;
              }
docs: Removes GCD from coefficients
  @param {Symbol} symbol
  @param {Factor} factors
  @returns {Symbol}