should be now correct and optimized for p2 / p3


git-svn-id: https://geuz.org/svn/gmsh/trunk@18962 59c8cabf-10d6-4a28-b43f-3936b85956c4
update of plugin AnalyseCurvedMesh. Can now compute metric. Interface improved. 


git-svn-id: https://geuz.org/svn/gmsh/trunk@18963 59c8cabf-10d6-4a28-b43f-3936b85956c4