minor changes to be able to load imagen (probably recent changes). Note that there is still a minor setup.py issue, in that the module transferfn, which lies in the hierarchy inside imagen, is not installed by the usual: python setup.py install
duty_cycle parameter is added to the class SquareGrating, to let the user generate an asymmetric SquareGrating
minor import change to remove a *
suppressing redundant softbounds in SquareGrating
comments added
correction of last commit + some merging
pull imagen in a consistent state
merging with last imagen
restore last inconsistency in patterngenerator.py
Merge pull request #22 from JoelChavas/master

Let SquareGrating be asymmetric