- expand MathFunctions.h to provide more functions, like exp, log...

- add cwiseExp(), cwiseLog()...
   --> for example, doing a gamma-correction on a bitmap image stored as
       an array of floats is a simple matter of:
         Eigen::Map<VectorXf> m = VectorXf::map(bitmap,size);
         m = m.cwisePow(gamma);
- apidoc improvements, reorganization of the \name's
- remove obsolete examples
- remove EIGEN_ALWAYS_INLINE on lazyProduct(), it seems useless.

doc/examples/class_FixedBlock.cpp

@@ -6,14 +6,14 @@ template<typename Derived>
 Eigen::Block<Derived, 2, 2>
 topLeft2x2Corner(MatrixBase<Derived>& m)
 {
-  return Eigen::Block<Derived, 2, 2>(m, 0, 0);
+  return Eigen::Block<Derived, 2, 2>(m.derived(), 0, 0);
 }
 
 template<typename Derived>
 const Eigen::Block<Derived, 2, 2>
 topLeft2x2Corner(const MatrixBase<Derived>& m)
 {
-  return Eigen::Block<Derived, 2, 2>(m, 0, 0);
+  return Eigen::Block<Derived, 2, 2>(m.derived(), 0, 0);
 }
 
 int main(int, char**)