RINGMesh 4.1.0 is out!

What is new in RINGMesh 4.1.0 ?

New thread safe logger:
- Each call to Logger::XXX will output consistently in the console in multithreading environment.
- The Logger uses variadic templates, you can use as many parameters as you want in the function.
Add possibility to run specific validity check on GeoModels (topology, geometry, all, ...)
ASCII surface STL export
First implementation of a stratigraphic column
Add Feflow export using .fem file. Support wells as discrete fractures and mixed element mesh.
Add symmetric entity relationships management, an entity is the boundary of another entity and the reverse is automatically set. Same things for the parents/child relations.
New version of the .gm file format which not contains the GEOL_FEATURE on Mesh Entities anymore.
Export to gmsh file format (V2).
Add MeshSet, a mesh composed from all the other mesh types (PointSet, Line, Surface and Volume).

Crash when GeoModelMesh was initialized before the GeoModelMeshEntity geometries were set.
Cannot delete Mesh in RINGMeshView.
Fix crash on RINGMeshView exit (Logger was still register).
RINGMesh now compiles when TetGen cmake option is set to off.
GeoModelMeshVertices was not cleared after a tetrahedralize step.

Refactoring of the io to have smaller files.
Explicit distinction between the denomination of GeoModelMeshEntity and GeoModelGeologicalEntity:
- Now, gmme_t are used to identify a GeoModelMeshEntity (with and index and a type).
- Now user who want to use GeoModelEntity has to give a particular attention on The type of GeoModelEntity because EntityType are not a std::string anymore. GeologicalEntityType and MeshEntityType inherit from the class EntityType.
Remove MeshAllD and inherited classes, user should only use Mesh0D, Mesh1D, Mesh2D or Mesh3D.
The GeoModelMesh has been modified according this modification.
Improve some designs by using the NRVO/RVO (Named Return Value Optimization)
Use C++11 smartpointers for all the pointers allocated on the heap
Remove complex inheritance design of the GeogramMesh and GeogramMeshBuilder classes
Add naming distinction between a facet (a boundary polygon of a cell) and a polygon (a surface mesh element)
Mesh Entities have no longer a GEOL_FEATURE.
Refactoring of the GeoModel graphics
Create enums for classifying cells (CellType) and polygons (PolygonType).

All third party files (zlib, geogram) are now in a "third_party" directory at the RINGMesh root.
Removal of ThreeJS third party.
Add formatter settings for Visual Studio 2013 (12.0) and Visual Studio 2015(14.0).
Formatters are uniform between Visual and Eclipse.
A cmake configuration file was created to ease the integration of RINGMesh in other software which is generated by cmake.
This file is cmake/RINGMeshConfig.cmake. See doxygen documentation (doc/dox/cmake_integration.dox) for more details.