Also fixes FitIncidentSpectrum.py and CalculatePlaczekSelfScattering so
that output workspace has same x units

Removes a warning from the help build.

RHEL7 builds running older versions of SciPy Howells function does not work,
SciPy 0.12.1 also lacks the derivative function for splines so in older RHEL7
builds the gaussconv solution calculate the derivative manualy, with slightly
less accuracy

Verification on binning for fit and calc now limits the min and
max values to the min and max of the InputWorkspace plus or minus
the bin width.

Also fist minor formatting issues in other files (improper whitespace)