ScriptLanguageIndex: give details on duplicates

In particular, it helps to know which JAR file each language came from.

Author: ctrueden

src/main/java/org/scijava/script/ScriptLanguageIndex.java

@@ -40,6 +40,7 @@
 import javax.script.ScriptEngineFactory;
 
 import org.scijava.log.LogService;
+import org.scijava.util.ClassUtils;
 import org.scijava.util.FileUtils;
 
 /**
@@ -175,8 +176,13 @@ private String overwriteMessage(final boolean overwrite, final String type,
 	{
 		return (overwrite ? "Overwriting " : "Not overwriting ") + //
 			type + " '" + key + "':\n" + //
-			"\tproposed = " + proposed.getClass().getName() + "\n" +
-			"\texisting = " + existing.getClass().getName();
+			"\tproposed = " + details(proposed) + "\n" +
+			"\texisting = " + details(existing);
 	}
 
+	/** Helper method of {@link #overwriteMessage}. */
+	private String details(final ScriptLanguage language) {
+		final Class<?> c = language.getClass();
+		return c.getName() + " [" + ClassUtils.getLocation(c);
+	}
 }