Assert bcid set names are different

This solves problems found when using MOOSE in tandem with libmesh due
to MOOSE’s implementation treating names as the “first-class” identifier

Resolves: libMesh#3489

Author: andcarl384

src/apps/meshbcid.C

@@ -44,7 +44,7 @@ void usage_error(const char * progname)
 
   exit(1);
 }
-
+std::map<std::string, int> bcids;
 int main(int argc, char ** argv)
 {
   LibMeshInit init(argc, argv);
@@ -90,7 +90,20 @@ int main(int argc, char ** argv)
 
   BoundingBox normals(minpt, maxpt),
               points(minpt, maxpt);
-
+  std::string side_set_name;
+  std::string node_set_name;
+  if (cl.search("--sideSetName"))
+    {
+      side_set_name = cl.next("");
+      assert(bcids.find(side_set_name) == bcids.end());
+      bcids.insert(std::pair<std::string, int> (side_set_name, bcid));
+    }
+  else if (cl.search("--nodeSetName"))
+    {
+      node_set_name = cl.next("");
+      assert(bcids.find(node_set_name) == bcids.end());
+      bcids.insert(std::pair<std::string, int> (node_set_name, bcid));
+    }
   if (cl.search("--minnormalx"))
     normals.min()(0) = cl.next(normals.min()(0));
   if (cl.search("--maxnormalx"))