Return fictional value from deprecated functions.
Respect returnin value in computeForceTorqueViscEl

More correct way of returning true/false in
Law2_ScGeom_ViscElPhys_Basic::go
Update Schwager2007 URL

Use the link on arxiv.org
Add one more paper
fix https://bugs.launchpad.net/yade/+bug/1368591 + remove a useless test
remove a temporary fix for https://bugs.launchpad.net/yade/+bug/923929, after better fix in https://github.com/yade/trunk/commit/4ea76ad6e47ac5074a389ad61712a0840e8560a5, thanks Anton
parallel removal of old interactions
replace LOG_ERROR by LOG_WARN for notifying deprecation of GravityEngine
improve falling back to 1-thread in parrallel collider (fix https://bugs.launchpad.net/yade/+bug/1368591)
fix missing brackets resulting in wrong permeability in periodic PFV
Fixed a bug that appeared when running the uniaxial-post.py script from examples. Edited py/post2d.py to capture exception while importing Vector3 from minieigen.
Correction of an error using psd() with monodisperse packings (false = False in python). Add of an explanatory message
point to Bourrier2013 for a partial explanation of the CohesiveFrictional contact law
fix doc regarding requestErase() - https://bugs.launchpad.net/yade/+bug/1370736, thanks Jan
Merge pull request #44 from fifthguy/master

Fixed a bug that appeared when running the uniaxial-post.py script from ...
Few changes in capillary doc: assumption of null wetting angle, hyperlinks, and some comments in source code
enable periodic simulations with Polhedron and Tetra
rename PolyhedraVolumetricLaw -> Law2_PolyhedraGeom_PolyhedraPhys_Veolumetric
One forgotten change during previous commit about TriaxialStressController <-> 3DTriaxialEngine ? https://github.com/yade/trunk/commit/77bc6d75b780bcbad5bdadc5bb3645badb009cd9
Correct contact tracking bugs for grids.
They essencially came from the new logic of laws that have to return booleans.