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/irda/irda.c

@@ -264,11 +264,8 @@ void irda(void* p) {
     gui->add_widget(gui, widget, GuiLayerFullscreen);
 
     // Red LED
-    // create pin
-    GpioPin led = led_gpio[0];
-
     // TODO open record
-    GpioPin* led_record = &led;
+    const GpioPin* led_record = &led_gpio[0];
 
     // configure pin
     gpio_init(led_record, GpioModeOutputOpenDrain);