added smoothed ps for control over aliasing in unit tests
(#304)
added header to smoothed file, works fine with table
(#304)
fixed duplication issue in lensing.py, also added docstring for kasier squires about aliasing
(#304)
finalized unit tests for kappa stuff on this branch, working OK but left a note about how I don't understand the slight sign fiddling I needed to do within buildGriddedShears
(#304)