fix straigthen // with ho geometry in 3d
fix edge // data
simplify the face barycenter computed (only on vertices and not for all geometric point)
 ->   fix ho geometry in 3d (Geo >= 3)
but it's strange, maybe a bug with face.G() with these ho geo
Merge branch 'develop' of https://github.com/feelpp/feelpp into develop
Update functionspace.hpp

Bug in THch - missing "+1"
fix major bug with simplex on geometric order 3 in 3d
add function that allow to save a geoentity (tetra, triangle,...) as a gmsh mesh file.
In particularly usefull to show the local numerotation of geometric points.
Ex :
    saveGeoEntityAsGMSHMesh(_geoentity=*mesh->beginElement(),_filename="myentityElt.msh");
    saveGeoEntityAsGMSHMesh(_geoentity=*mesh->beginFace(),_filename="myentityFace.msh");
    saveGeoEntityAsGMSHMesh(_geoentity=*mesh->beginEdge(),_filename="myentityEdge.msh");
add boost parameter
more cores
fix test
Merge branch 'develop' of https://github.com/feelpp/feelpp into develop
does not exist anymore
up
minor
added laplacian in polar coordinates
Merge branch 'develop' of https://github.com/feelpp/feelpp into develop
fix eigen backend for sprase matrices
add a parameter h  to control hsize for the basic geometries
which can be controlled 
 - from the command line using ```gmsh.hsize```
 - from the code itself 
   ```
   auto mesh = unitSquare( 0.1 );
   ```
support for both eigen (sparse) and eigen (dense) backend.
the eigen dense backend should not be used in pratice or in very special cases
add testsuite for ginac