TIFF support added
cleaned up inheretance in parse, new TIFF test
reduced test load
updated travis yaml
test update
fixed polarization correction code, resolve #67
made photons scattered per shot an optional arg in Beam, #65
merged master -- resolved conflicts
modified setup.py to warn about fftw
working for intra correlations
inter order N method using FFTs
added tests for no fftw
updated tests