Bugs in LAW=7 and LAW=9

[HunterBelanger]

For LAW=7 (Maxwellian), the definition of the normalization constant I does not match the definition found in the ENDF manual.

For LAW=9 (Evaporation), the form of the distribution does not agree with that found in the ENDF manual (should be E_{out} in the numerator, and not \sqrt{E_{out}}). There is a note however which explicitly states that the form of the distribution for Maxwellian and Evaporation should be the same. Assuming that the ENDF version of these distributions is correct, then this note is also inaccurate.

I have fixes prepared for both of these, I just want to make sure that the LAW=9 discrepancy is indeed a bug (as the explicit note makes me somewhat suspicious).