XERCESC configuration : take env variable when defined
Merge pull request #52 from vvidal/master

Minor modifications for easier testing : add a manifold mesh and 2 non-manifold meshes + add Data directory depency in Test (data used for testing should be put in the Data directory)
cmake and ui updates
delete Armadillo.raw too big for github...
Add a new data structure for non-manifold meshes (not finished yet)
Merge branch 'master' of github.com:MEPP-team/Gharial
Add a new data structure for non-manifold meshes