Two changes to existing model functions:
1) For the 2-yukawa model: Added conditions to enforce Z1>Z2. If this condition is not met, then a valid-looking (but incorrect) S(q) may be returned. These conditions were identified and satisfied within Yun's original Matalb code but were not transferred to the Igor code or XOP. These conditions are enforced within the Igor code before sending to either the XOP or local Igor code.
2) For the Teubner-Strey model: The coefficients have been re-written in terms of the two length scales and a proper absolute scaling. The Macro to calculate the length scales now also reports the amphiphilicity factor.
3) The help file entries for both of these functions have been appropriately updated.
