569: merge bug fixe commits:
1fa9114: rots tick may not be disabled if a task is blocked, i.e., waiting for a certain time for an event;
35f5bee: sniff mode was not requested if accelerometer is disabled;
73966a1: if portEXIT_CRITICAL was called from an ISR, it was enabling interrupts during an ISR. However, some FreeRTOS functions like xTaskRemoveFromEventList (used by SendMessageToQueueFromIsr) require that interrupts are disabled when they are called. This occasionally resulted in wrong thread context switches. For example, the Wrapper task frooze occaisionally, resulting in watch dog resets.
75abf83: interrupts must be enabled before the serial RAM is initialized.