antenna modif + others 

+ add pattern method to antenna	ba0f2c3
+ added a doadod method to TUchannel	6b30f1f
+ added a Fpatt method to generate a antenna pattern	518e594
+ correct a bug in buildGi in order to take into account all of subsegm… …	3d9d96f
+ minor change (replace try except by hasattr)	7d6ebbd
+ add antenna pattern to show3 method, if S.tx and S.rx are radionodes	eeec1b3
+ check in bsignal __init__ for further broadcasting approach	0b3e150
+ show3 now display antenna pattern	a3679d4
+ Geomoff obsject default name changed