Revert "Simplify Group::IsVisible(), GroupsInOrder()."

This reverts commit 022d012.

The commit above has caused crashes during pruning.

src/generate.cpp

@@ -57,8 +57,15 @@ bool SolveSpaceUI::PruneOrphans() {
 bool SolveSpaceUI::GroupsInOrder(hGroup before, hGroup after) {
     if(before.v == 0) return true;
     if(after.v  == 0) return true;
-    int beforep = SK.GetGroup(before)->order;
-    int afterp = SK.GetGroup(after)->order;
+
+    int beforep = -1, afterp = -1;
+    int i;
+    for(i = 0; i < SK.groupOrder.n; i++) {
+        hGroup hg = SK.groupOrder.elem[i];
+        if(hg.v == before.v) beforep = i;
+        if(hg.v == after.v)  afterp  = i;
+    }
+    if(beforep < 0 || afterp < 0) return false;
     if(beforep >= afterp) return false;
     return true;
 }

src/group.cpp

@@ -44,8 +44,7 @@ void Group::AddParam(IdList<Param,hParam> *param, hParam hp, double v) {
 
 bool Group::IsVisible() {
     if(!visible) return false;
-    Group *active = SK.GetGroup(SS.GW.activeGroup);
-    if(order > active->order) return false;
+    if(SS.GroupsInOrder(SS.GW.activeGroup, h)) return false;
     return true;
 }