Merge pull request #194 from buguen/master

Fixing reciprocity bug
Clear notebooks
add pattern method to antenna
typo in index.html FronPage
cleaning notebooks
added a doadod method to TUchannel
added a Fpatt method to generate a antenna pattern
correct a bug in buildGi in order to take into account all of subsegments
of a segment when one is metal
minor change (replace try except by hasattr)
add antenna pattern to show3 method, if S.tx and S.rx are radionodes
checn in bsignal __init__ for further broadcasting approach
show3 now display antenna pattern
Geomoff obsject default name changed
Merge pull request #195 from niamiot/master

+ generate a anetnna pattern
+ various display imporvement for antenna pattern
+ buildGi correclty manage subsegment
reconciliation of body time and trajectory time in posvel
Merge branch 'master' of https://github.com/pylayers/pylayers