modif in post-Friis
adding figure for illustrating D2.4 (defstr layout)
add energy function in Tchannel.py
update test_Friis.py
Merge branch 'master' of https://github.com/pylayers/pylayers
bug fix in methods plod and doadod from channel class
Merge branch 'master' of github.com:pylayers/pylayers into HEAD
- new antenna functions (Wireplate and Omni)
- bug fix
Merge branch 'new_branch_name'

Conflicts:
	pylayers/antprop/channel.py
add new notebook
bug fix in Signature.propath (bug if no airwall in the structure)
- bug fix in plotd Ctilde and Tchannel (polar 2nd axis is now in degree)
- rewrite doadod for Ctilde and Tchannel (call plotd)
change default seek of signature algorithm in run4