removed the numpy.fft prefixes in convolve, and added the brickwall filter
removed the numpy.fft prefixes in convolve, and added the brickwall filter

jcesardasilva/agpy,ufoym/agpy,ufoym/agpy,tectronics/agpy,ufoym/agpy,Leotrinos/agpy,jcesardasilva/agpy,Leotrinos/agpy,tectronics/agpy,ufoym/agpy,tectronics/agpy,jcesardasilva/agpy,Leotrinos/agpy,Leotrinos/agpy,tectronics/agpy,jcesardasilva/agpy