acefc_feature_1_updates

[dlopezaldama]

1. Correction to prevent losing the penultimate node in the unified energy grid
2. Corrected calculation for MF6/LAW5/LTP=2 (residual cross-section expansion).
   Implemented linearization of the elastic scattering for MF5/LTP>2 (nuclear plus interference).
   Corrected treatment of identical particles for MF6/LAW5/LTP>2.
3. Corrected/enhanced treatment of MF6/LAW7
4. Corrected and enhanced subroutine acelf6, including the addition of new
   warning messages, improvements to the secondary energy grid calculation
   for MF6/LAW=6, a safer implementation of the smoothing option at low
   energies for MF6/LAW=1/LANG=2 to avoid energy grid misordering, a
   correction in the conversion from LAW=1 to LAW=7 when NEWFOR=0, and
   prevention of potential division-by-zero errors.
5. Updates to protect the construction of the union list of discrete photons
   and to avoid potential division by zero errors
6. Added code to prevent errors caused by invalid pointers or division by zero.
7. acelcp updates: Improved calculation of heating, using a better approximation for
   conversion between the centre-of-mass and laboratory reference frames. Corrected the
   probability of validity for the energy law in ACE-formatted files (laws 33, 66,
   and 67).More accurate treatment of allowed interpolation laws and their use in
   integrations.
8. Subroutine change: Correction for law44
9. acefix correction: Take mass ratios for p, d, t, He-3, and alphas from the phys module
10. consis updates: Include checking of law67 and minor changes in a few consistency tests
11. update law67 plotting capabilities, plus a few additional corrections for
    aplodd, aploxp and getl7
12. Store thresholds with 9-digit precision for better consistency
13. Increase array size, use big=1.0e10 consistently, and clarify photon-production
    output message for incident charged particles