- rework the coefficients API

- make vectors use a separate loop unroller, so that copying a
row-vector into a col-vector is now possible
- add much more documentation
- misc improvements

doc/example.cpp

@@ -1,18 +1,18 @@
 #include <Eigen/Core.h>
 
-USING_EIGEN_DATA_TYPES
+USING_PART_OF_NAMESPACE_EIGEN
 
 using namespace std;
 
 template<typename Scalar, typename Derived>
-void foo(const Eigen::MatrixBase<Scalar, Derived>& m)
+void foo(const MatrixBase<Scalar, Derived>& m)
 {
   cout << "Here's m:" << endl << m << endl;
 }
 
 template<typename Scalar, typename Derived>
 Eigen::ScalarMultiple<Derived>
-twice(const Eigen::MatrixBase<Scalar, Derived>& m)
+twice(const MatrixBase<Scalar, Derived>& m)
 {
   return 2 * m;
 }