Merge branch 'feat/check-PATH' into experimental

* feat/check-PATH:
  Tweak of path finding
  feat(process-manager): check PATH folders for NEURON executables also
  chore(process-manager): add new NEURON release versions

src/main/java/org/neuroml/export/neuron/ProcessManager.java

@@ -34,13 +34,17 @@ public static File findNeuronHome() throws NeuroMLException
         String nrnEnvVar = System.getenv(NeuronWriter.NEURON_HOME_ENV_VAR);
         String[] knownVersions = new String[]
         {
-            "7.5", "7.4", "7.3", "7.2", "7.1", "6.2", "6.1", "6.0"
+            "8.2.1", "8.2.0", "8.1.0", "8.0.2", "8.0.1", "8.0.0",
+            "7.8.2", "7.8.1", "7.7.1", "7.6.7", "7.5", "7.4", "7.3", "7.2", "7.1",
+            "6.2", "6.1", "6.0"
         };
 
-        if (nrnEnvVar != null)
+        /* If NEURON_HOME is defined, it gets priority */
+        if (nrnEnvVar != null && nrnEnvVar.length()>0)
         {
             options.add(nrnEnvVar);
         }
+        /* If NEURON_HOME is not defined, check all the usual suspects */
         else if (Utils.isWindowsBasedPlatform())
         {
             for (String ver : knownVersions)
@@ -52,6 +56,12 @@ else if (Utils.isWindowsBasedPlatform())
         }
         else if (Utils.isMacBasedPlatform())
         {
+            /* Check folders in PATH */
+            for (String folder: System.getenv("PATH").split(";")) {
+                options.add(folder);
+            }
+
+            /* Other possible folders */
             for (String ver : knownVersions)
             {
                 options.add("/Applications/NEURON-" + ver + "/nrn/powerpc");
@@ -63,6 +73,13 @@ else if (Utils.isMacBasedPlatform())
         }
         else if (Utils.isLinuxBasedPlatform())
         {
+
+            /* Check folders in PATH */
+            for (String folder: System.getenv("PATH").split(";")) {
+                options.add(folder);
+            }
+
+            /* Other possible folders */
             options.add("/usr");
             options.add("/usr/local");
             options.add("/usr/local/nrn/x86_64");
@@ -84,7 +101,7 @@ else if (Utils.isLinuxBasedPlatform())
 
         String env = Utils.sysEnvInfo("  ");
 
-        throw new NeuroMLException("Could not find NEURON home directory! Options tried: " + options
+        throw new NeuroMLException("Could not find NEURON home directory! Options tried here: " + options
             + "\nThe NEURON executable which is sought inside this directory is: " + nrnExe + ". \n\n"
             + "Try setting the environment variable " + NeuronWriter.NEURON_HOME_ENV_VAR
             + " to the location of your NEURON installation (up to but not including bin), e.g.\n\n"