ensure log file exists and is empty for a run

Author: madhephaestus

src/main/java/com/neuronrobotics/bowlerstudio/BowlerKernel.java

@@ -422,7 +422,11 @@ private static void startupProcedures(String[] args)
 			fail();
 		}
 		CSGDatabase.setInstance(new CSGDatabaseInstance(new File(ScriptingEngine.getWorkspace().getAbsoluteFile() + "/csgDatabase.json")));
-		Log.setFile(new File(ScriptingEngine.getWorkspace().getAbsoluteFile() + "/kernelLog.txt"));
+		File logfile = new File(ScriptingEngine.getWorkspace().getAbsoluteFile() + "/kernelLog.txt");
+		if(logfile.exists())
+			logfile.delete();
+		logfile.createNewFile();
+		Log.setFile(logfile);
 		Log.enableDebugPrint();
 		ScriptingEngine.gitScriptRun(CSGDatabase.getInstance(),"https://github.com/CommonWealthRobotics/DeviceProviders.git", "loadAll.groovy",
 				null);