Add a tutorial page on the Map class, and add a section to FunctionsTakingEigenTypes about multiple-argument functions and the pitfalls when using Map/Expression types.

doc/C09_TutorialSparse.dox

@@ -4,7 +4,7 @@ namespace Eigen {
     \ingroup Tutorial
 
 \li \b Previous: \ref TutorialGeometry
-\li \b Next: TODO
+\li \b Next: \ref TutorialMapClass
 
 \b Table \b of \b contents \n
   - \ref TutorialSparseIntro
@@ -318,7 +318,7 @@ The compute() method is equivalent to calling both analyzePattern() and factoriz
 Finally, each solver provides some specific features, such as determinant, access to the factors, controls of the iterations, and so on.
 More details are availble in the documentations of the respective classes.
 
-\li \b Next: TODO
+\li \b Next: \ref TutorialMapClass
 
 */