Fix compilation issues with icc and g++ < 4.1. Those include:

- conflicts with operator * overloads
 - discard the use of ei_pdiv for interger
   (g++ handles operators on __m128* types, this is why it worked)
 - weird behavior of icc in fixed size Block() constructor complaining
   the initializer of m_blockRows and m_blockCols were missing while
   we are in fixed size (maybe this hide deeper problem since this is a
   recent one, but icc gives only little feedback)

Eigen/src/Geometry/AngleAxis.h

@@ -74,7 +74,7 @@ public:
   inline AngleAxis(const QuaternionType& q) { *this = q; }
   /** Constructs and initialize the angle-axis rotation from a 3x3 rotation matrix. */
   template<typename Derived>
-  inline AngleAxis(const MatrixBase<Derived>& m) { *this = m; }
+  inline explicit AngleAxis(const MatrixBase<Derived>& m) { *this = m; }
 
   Scalar angle() const { return m_angle; }
   Scalar& angle() { return m_angle; }