fix for #273 compatibility of boards manager change with alder arduino versions

Author: jantje

it.baeyens.arduino.core/src/it/baeyens/arduino/tools/ArduinoHelpers.java

@@ -778,7 +778,9 @@ public static void setTheEnvironmentVariables(IProject project, ICConfigurationD
 	setTheEnvironmentVariablesSetTheDefaults(contribEnv, confDesc, platformFilename);
 
 	// process the dump file from the arduino IDE
-	setTheEnvironmentVariablesAddAFile(contribEnv, confDesc, anduinoIDEEnvNamesPath);
+	if (anduinoIDEEnvNamesFile.exists()) {
+	    setTheEnvironmentVariablesAddAFile(contribEnv, confDesc, anduinoIDEEnvNamesPath);
+	}
 
 	// process the platform.txt file first. This way the boards.txt will
 	// overwrite the default settings

it.baeyens.arduino.core/src/it/baeyens/arduino/ui/ArduinoPreferencePage.java

@@ -135,9 +135,12 @@ private boolean showError(String dialogMessage) {
      */
     @Override
     public boolean performOk() {
-	if (!testStatus())
+	if (!mIsDirty) {
+	    return true;
+	}
+	if (!testStatus()) {
 	    return false;
-
+	}
 	if (mArduinoIdeVersion.getStringValue().compareTo("1.5.0") < 0) {
 	    showError("This plugin is for Arduino IDE 1.5.x. \nPlease use V1 of the plugin for earlier versions.");
 	    return false;