change gmsh.info links to https (as well as a few others, where it makes sense) + use relative paths in img src

Correct Hxt embedded surface Brep

See merge request !351

I thought the BRep was only containing the bounding surfaces/lines that defines a volumes/surface, and that it did not contain the embeded element. Actually, the BRep should contain those elements.

Hxt new size options

See merge request !349

add createGeometry to discreteRegion, so that we can selectively choose which discrete volumes we want to remesh

Fix some more ODR violations in MMG3D

See merge request !348

MMG_endcod is an identical definition in mmg3dlib.c, which also uses
the same global MMG_ctim/MMG_imprim variables. Defining the variables
twice is an ODR violation.

The analar state variables are only reset and printed in MMG_mmg3d1,
MMG_mm3d4, so move the definition to analar.c.

Another ODR violation fix.

new mesh/getJacobian() function to retrieve Jacobian data for a single element. This can be useful e.g. for post-processing, when one wants to evaluate the Jac at arbitrary locations in a mesh and where the bulk evaluation of Jacs is ill-suited.

getVertexVTK for Prism6

See merge request !347

Hxt refine dev

See merge request !346

Fix mmg detection

See merge request !345

When countDiscrete is false, getMeshStatus() should only return "dim" if all "dim"-dimension entities are actually meshed.

With the api, we can end up in situations where a model is meshed, then is modified by adding some entities. Meshing again should not conclude that the existing mesh is available, as it can be incomplete.

This fixes #897.