<h3>General</h3>
<ol>
+ <li> <p>
+ Extended: Up to now, in 3D only 'orientable' meshes could be used in
+ deal.II, i.e. all lines are in standard orientation and the faces can be
+ either in standard orientation or with a reversed normal. In order to
+ enable the treatment of all purely hexahedral meshes, this interface
+ (only the boolean flag <tt>face_orientation</tt> so far) has
+ been extended by new flags <tt>face_flip</tt> and <tt>face_rotation</tt>,
+ denoting a face which is rotated against the 'standard face' by 180 and 90
+ degrees, respectively. Furthermore, there is a new flag
+ <tt>line_orientation</tt> with obvious meaning.
+ <br> These flags have to be respected during creation and refinement of a
+ triangulation, when projecting quadrature points to faces or when the dof
+ indices on a cell are extracted. Furthermore, asking for vertices and
+ lines of cells is in some cases a bit more complicated. The same applies,
+ for example,
+ to the extraction of the information, which child of a neighbor is behind
+ a given subface. However, this infomation is supplied by various
+ functions in <code class="class">GeometryInfo</code>. As a rule-of-thumb:
+ if you want to use non-standard meshes, all occurances of
+ <tt>face_orientation</tt> have to be supplemented by <tt>face_flip</tt>
+ and <tt>face_rotation</tt>.
+ <br> In order to reduce the impact of possible bugs, the grid is still given to
+ <code class="class">GridReordering</code>, which now returns the original
+ connectivity if the reordering was not possible.
+ <br> A more detailed document concerning these topics will be available
+ in the future.
+ <br>
+ (Tobias Leicht 2007/02/09)
+ </p>
+
<li> <p>
New: a program <tt>reconfigure</tt> has been added to the
deal.II main directory, which reruns <tt>configure</tt> with