fix multithread logic in template app, update gpio HAL (#250)

* fix multithread logic
* more buffer for dallas id string
* update apps to use new logic
* delay_us small speedup
* add consant qualifier to gpio records and some core api
* fix some apps to use simpler method of getting gpio record
* fix ibutton app, stupid stack problem

applications/sd-card-test/sd-card-test.cpp

@@ -95,6 +95,8 @@ void SdTest::run() {
     gpio_init(red_led_record, GpioModeOutputOpenDrain);
     gpio_init(green_led_record, GpioModeOutputOpenDrain);
 
+    app_ready();
+
     detect_sd_card();
     show_warning();
     init_sd_card();