Update README
Merge branch 'master' of https://github.com/pylayers/pylayers
 add r2d and r3d directory to pylayers/data
(use .void)
Merge pull request #182 from niamiot/master

 add r2d and r3d directories
update cla doc
update notebook TOC
add __repr__ in agent
 add __repr__ for
- Agent
- Person
- Network
Merge branch 'master' of github.com:pylayers/pylayers
Merge pull request #183 from niamiot/master

add __repr__ to Agent / Network /Peronn
update cla doc
update ipynb TOC
improvement in Rays:
- rays.show3 now requires a layout as input (replace strucname)
- rays.show3 has now a center parameter (to center the layout )
- Rays has now a self.is3D, self.filled (interactions filled),
  self.evaluated (interactions evaluated)
- rays.show display the rays index if self.filled
bug fix in backtrace:
- add a tolerance on alpha and beta in signature.backtrace
This temporaly resolve the issue when a ray ouput into a corner.
To be updated when diffraction will be implemented
clear notebooks
Merge pull request #184 from niamiot/master

Imporvement in rays + bugfix in backtrace
modif in rays.py
Merge branch 'master' of https://github.com/pylayers/pylayers
change details in layout
adding test multiwall
fixing figure in simulation notebook
clear notebook