fix data files

VP1GeometrySystems/share/gmexMatVisAttributes.json

 {
-    "DetVisAttributes": [
+    "MatVisAttributes": [
         {
             "ambient": {
                 "B": 0.5699999928474426,

VP1GeometrySystems/share/gmexVolVisAttributes.json

 {
-    "DetVisAttributes": [
+    "VolVisAttributes": [
         {
             "ambient": {
                 "B": 1.0,

VP1GeometrySystems/src/VisAttributes.cxx

@@ -260,6 +260,7 @@ DetVisAttributes::DetVisAttributes() {
   for (const std::string & s : locations ) {
     std::string userFile=s+std::string("gmexDetVisAttributes.json");
     if (access(userFile.c_str(),R_OK)==0) {
+      std::cout << userFile << std::endl;
       std::ifstream in(userFile);
       auto j=json::parse(in);
       for (const json & element : j["DetVisAttributes"]) {
@@ -307,6 +308,7 @@ MatVisAttributes::MatVisAttributes() {
   for (const std::string & s : locations ) {
     std::string userFile=s+std::string("gmexMatVisAttributes.json");
     if (access(userFile.c_str(),R_OK)==0) {
+      std::cout << userFile << std::endl;
       std::ifstream in(userFile);
       auto j=json::parse(in);
       for (const json & element : j["MatVisAttributes"]) {
@@ -348,6 +350,7 @@ VolVisAttributes::VolVisAttributes() {
   for (const std::string & s : locations ) {
     std::string userFile=s+std::string("gmexVolVisAttributes.json");
     if (access(userFile.c_str(),R_OK)==0) {
+      std::cout << userFile << std::endl;
       std::ifstream in(userFile);
       auto j=json::parse(in);
       for (const json & element : j["VolVisAttributes"]) {