Added ChGlyphs as a visualization asset that can be used to show points or vectors (or other stuff like coordinates or tensors, in future).
Those symbols are frequently used for FEM postprocessing, ex. they are used in the unit_FEM thank to the ChVisualizationFEMmesh converter.
The way those glyps (simple simbols) are drawn depend on the rendering subsystem: currently only the IRRLICHT unit supports glyphs rendering. The POVray support will be done later.
Refactoring. The old ChLcpKstiffness and ChLcpKstiffnessGeneric classes have been renamed to ChLcpKblock and ChLcpKblockGeneric.
This because in the LCP / CCP/ VI, those objects can be used to define a matrix sparse block that is not necessarily a stiffness matrix (it is a stiffness matrix in the case of linear elastic problems, but in more general sense it is just a block in the KKT matrix).
Improvements to the FEM code.
Experimental support for Poisson3D problems and diffusion problems, ex. the thermal and electrostatic problem.
Experimental support of Euler-Bernoulli beams.
Work in progress.
Merge branch 'develop' of https://github.com/projectchrono/chrono
Added capability of storing coordsystems as glyphs (ex. useful for showing the nodes of FEM beams, that also have rotations)
The rendering subsystems must support painting this type of glyph.
Added GetInverse() for generic quaternions (for unit norm quaternions it is still better to use GetConjugate() that is the same)
Added first tests code for testing the ChElementBeamEuler, that is an Euler-Bernoulli type of beam.
Note!!! this is not yet safe, it must be validated, and features are not yet complete!
Added a general way to specify the position and rotation of a visual asset. It might be cleaner to do this at the geometry level but each geometry type has it’s own specific data elements.
Add ChMaterialSurfaceDEM, a class defining material properties for penalty method (DEM) contact.
Add simple demo for DEM contact

Ball bouncing off a box
Cleanup contact force calculation.

Refactor the ChContactDEM class for clarity, improved efficiency, and memory usage.
Irrlicht demos using DEM contact.
Fixed bug in eigenvalue computation in 3x3 matrix (results were not reported). This function was never used, anyway.
Slower movements for Irrlicht camera when pressing arrows and Pgup/down keys in keyboard.
Computation of principal stresses/strains for tensors
Prototype of a parser for .INP files from Abaqus tetahedral meshes. To be improved.
Various new features and fixes for the unit_FEM unit.
Better rendering of meshes in Irrlicht.
Rendering of beams.
Demo for Eulero-Bernoulli 3D beam.
Demo for electrostatics / permittivity of media
Demo for thermal (Poissono PDE with diffusion)
Other various new features.
Merge branch 'develop' of https://github.com/projectchrono/chrono into develop
Clean-up.

Use the DEM solver (which is just SOR but skips any unilateral constraint work),  but make sure to set non-zero number of maximum iterations (for the bilateral constraint)