issue #393 delete json files when they fail to be parsed

Author: jantje

it.baeyens.arduino.core/src/it/baeyens/arduino/managers/Manager.java

@@ -240,6 +240,7 @@ static private void loadPackageIndex(String url, boolean forceDownload) {
 	    } catch (Exception e) {
 		Common.log(new Status(IStatus.ERROR, Activator.getId(),
 			"Unable to parse " + packageFile.getAbsolutePath(), e)); //$NON-NLS-1$
+		packageFile.delete();// Delete the file so it stops damaging
 	    }
 	}
     }