Fix energy grid for photoelectric cross sections

Comparing binding energies in incoh.data and xcom_photo.data I found
that for elements Z=88 and Z=90 the L1 binding energy in xcom_photo.data
was four times larger than the one found in incoh.data. The differences
in the L2 and L3 binding energies were 5% and 20%, respectively.

These large discrepancies were traced to an error in the energy value
immediately below the 100 keV point near their K shell binding energy
Eb_K. The K shell binding energies for these elements lies above 100 keV
and two equal energy points are used at the K edge, representing the
jump in the cross section. However the energy point below 100 keV was
also set to Eb_K rather than 80 keV.

HEN_HOUSE/data/xcom_photo.data

@@ -3039,7 +3039,7 @@
   -3.99083  10.24246  -3.99083  10.58431  -3.95094  10.48431  -3.95094  10.62862
   -3.91202  10.52969  -3.70929  10.01091  -3.60792   9.74893  -3.50656   9.48494
   -3.36272   9.10677  -3.21888   8.72534  -2.99573   8.12917  -2.81341   7.63820
-  -2.26412   6.85783  -2.30259   6.24978  -2.26411   6.14526  -2.26411   7.63434
+  -2.52573   6.85783  -2.30259   6.24978  -2.26411   6.14526  -2.26411   7.63434
   -1.89712   6.69121  -1.60944   5.94149  -1.20397   4.89859  -0.91629   4.18388
   -0.69315   3.65196  -0.51083   3.23396  -0.22314   2.60712   0.00000   2.14862
    0.02176   2.10523   0.22314   1.71290   0.40547   1.37220   0.69315   0.86836
@@ -3106,7 +3106,7 @@
   -4.11657  10.67475  -3.92748  10.16045  -3.92748  10.51813  -3.91202  10.46482
   -3.88869  10.40729  -3.88869  10.55111  -3.69763  10.06444  -3.50656   9.57290
   -3.36272   9.19732  -3.21888   8.81789  -2.99573   8.22443  -2.81341   7.73543
-  -2.21045   6.95845  -2.30259   6.35333  -2.21045   6.10323  -2.21045   7.56993
+  -2.52573   6.95845  -2.30259   6.35333  -2.21045   6.10323  -2.21045   7.56993
   -1.89712   6.76872  -1.60944   6.02538  -1.20397   4.98839  -0.91629   4.27778
   -0.69315   3.74880  -0.51083   3.33292  -0.22314   2.70872   0.00000   2.25077
    0.02176   2.20739   0.22314   1.81548   0.40547   1.47453   0.69315   0.97078