REfs #8373 Added comparison of fit parameters

modified:   StretchedExpFTTest.py
Refs #8373 The function is finally fitting

modified:   ../../../../plugins/functions/StretchedExpFT.py
modified:   ../functions/StretchedExpFTTest.py
Refs #8373 Finished writing the test

modified:   StretchedExpFT.py
modified:   StretchedExpFTTest.py