Flexible: compute the geometric stiffness matrix for principal stretches, so scenes using principal stretches can now be assembled. Note that only brute force implementations for 3D->3D and 3D->2D have been copied from maple, it could be great to be able to extract a general algorithm for any dimensions. 

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9274 b7f1a160-662a-0410-a6d8-bea165342f16
Flexible: [Teran05]'s SSPD stabilization applied on dStress/dF does not seem possible for dStress/dPrincipalStretches

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9275 b7f1a160-662a-0410-a6d8-bea165342f16
ADD: cmake Qwt
FIX: cmake SofaGuiQt

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9276 b7f1a160-662a-0410-a6d8-bea165342f16
ADD: Qwt CMakeLists.txt

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9277 b7f1a160-662a-0410-a6d8-bea165342f16
projection of a 2x2 symmetric matrix to its closest symmetric, positive semi-definite matrix for a matrix that is not contiguous in memory

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9278 b7f1a160-662a-0410-a6d8-bea165342f16
fixed typos

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9279 b7f1a160-662a-0410-a6d8-bea165342f16
FIX: cmake Qwt on Windows
FIX: QT ui file generation for SofaGuiQt



git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9280 b7f1a160-662a-0410-a6d8-bea165342f16
REMOVE: irrelevant log message

git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9281 b7f1a160-662a-0410-a6d8-bea165342f16
working on Mapping_test.



git-svn-id: svn://scm.gforge.inria.fr/svnroot/sofa/trunk@9282 b7f1a160-662a-0410-a6d8-bea165342f16