Document QuaternionBase, minor doc improvements.

* Document class QuaternionBase so that docs for members are displayed.
* Remove obsolete \redstar refering to Array module
* Fix typo in Constants.h
* Document EIGEN_NO_AUTOMATIC_RESIZING

doc/Doxyfile.in

@@ -206,7 +206,6 @@ ALIASES                = "only_for_vectors=This is only for vectors (either row-
                          "qr_module=This is defined in the %QR module. \code #include <Eigen/QR> \endcode" \
                          "svd_module=This is defined in the %SVD module. \code #include <Eigen/SVD> \endcode" \
                          "label=\bug" \
-                         "redstar=<a href='#warningarraymodule' style='color:red;text-decoration: none;'>*</a>" \
                          "matrixworld=<a href='#matrixonly' style='color:green;text-decoration: none;'>*</a>" \
                          "arrayworld=<a href='#arrayonly' style='color:blue;text-decoration: none;'>*</a>" \
                          "note_about_arbitrary_choice_of_solution=If there exists more than one solution, this method will arbitrarily choose one." \

doc/I14_PreprocessorDirectives.dox

@@ -29,6 +29,9 @@ This page lists the preprocesor tokens recognised by %Eigen.
    Defaults to the #IOFormat constructed by the default constructor IOFormat().
  - \b EIGEN_INITIALIZE_MATRICES_BY_ZERO - if defined, all entries of newly constructed matrices and arrays are
    initializes to zero, as are new entries in matrices and arrays after resizing. Not defined by default.
+ - \b EIGEN_NO_AUTOMATIC_RESIZING - if defined, the matrices (or arrays) on both sides of an assignment 
+   <tt>a = b</tt> have to be of the same size; otherwise, %Eigen automatically resizes \c a so that it is of
+   the correct size. Not defined by default.
 
 
 \section TopicPreprocessorDirectivesAssertions Assertions

doc/QuickReference.dox

@@ -440,10 +440,10 @@ Eigen provides several reduction methods such as:
 \link DenseBase::sum() sum() \endlink, \link DenseBase::prod() prod() \endlink,
 \link MatrixBase::trace() trace() \endlink \matrixworld,
 \link MatrixBase::norm() norm() \endlink \matrixworld, \link MatrixBase::squaredNorm() squaredNorm() \endlink \matrixworld,
-\link DenseBase::all() all() \endlink \redstar,and \link DenseBase::any() any() \endlink \redstar.
+\link DenseBase::all() all() \endlink, and \link DenseBase::any() any() \endlink.
 All reduction operations can be done matrix-wise,
-\link DenseBase::colwise() column-wise \endlink \redstar or
-\link DenseBase::rowwise() row-wise \endlink \redstar. Usage example:
+\link DenseBase::colwise() column-wise \endlink or
+\link DenseBase::rowwise() row-wise \endlink. Usage example:
 <table class="manual">
 <tr><td rowspan="3" style="border-right-style:dashed;vertical-align:middle">\code
       5 3 1