working mostly on documentation
some fixing in bsignal.py
typos in localization docstring
changing speed of light
typos
Merge pull request #67 from buguen/master

pull request test
modification in simulem.rst
Merge branch 'master' of https://github.com/pylayers/pylayers
add README
add README
fix bug in del_edge
modifictaion in layout
commit change
add tocmanual.rst