Fix photo-electron emission with relaxation (#298)

Emit a photo-electron with the photon energy (instead of depositing the
photon energy locally) when $EADL_RELAX = true and the photon interacts
with a shell below L3.

Likewise, emit a photo-electron (instead of depositing energy locally)
when $EADL_RELAX = true and the photon energy falls below the binding
energy of the M2 shell, i.e., binding_energies($MXSHELL,iZ).

HEN_HOUSE/src/egsnrc.mortran

@@ -5092,9 +5092,16 @@ IF( iedgfl(irl) ~= 0 ) [ " User requested atomic relaxations "
  " is interacting with. "
  " left for now as before, to be changed!!! "
  IF( peig <= binding_energies($MXSHELL,iZ) )
- [ "Below N-shell -> local energy deposition "
- edep = peig;
- e(np) = pzero; "wt(np) = 0;"
+ [ "Outer shells, no atomic relaxation"
+ IF ($EADL_RELAX)[
+ "EADL relax: Below M2-shell -> just emit e- "
+ iq(np) = -1;
+ e(np) = peig + prm;
+ ]
+ ELSE["Default: Below N-shell -> local energy deposition "
+ edep = peig;
+ e(np) = pzero; "wt(np) = 0;"
+ ]
  ]
  ELSE ["Above N-shell -> sample the shell the photon is interacting with"
  $RANDOMSET br; /* ftot = 1; */
@@ -5111,9 +5118,9 @@ IF( iedgfl(irl) ~= 0 ) [ " User requested atomic relaxations "
  "**************** from previous EGSnrc approach as it doesn't"
  " generate e- nor x-rays from <M> and <N> shells."
  IF ($EADL_RELAX & k > 4)[
-  "No interaction below L3 with EADL"
- edep = peig;
- e(np) = pzero;
+ "No initial vacancy below L3 for now, just emit e-"
+ iq(np) = -1;
+ e(np) = peig + prm;
  ]
  ELSE["EADL: Interacts with K,L1..L3 shells"
  "default: Interacts with K,L1..L3,<M>, and <N> shells"