Boot apps refactored (#498)

- Specify launcher via menuconfig
- Specify auto-start app via menuconfig
- Implement more rigid boot.properties fallbacks
- Devices with tiny screen now auto-start ApWebServer
- ApWebServer UI fixes

Tactility/Include/Tactility/settings/BootSettings.h

@@ -17,7 +17,7 @@ struct BootSettings {
  * then it will try to load the one from the data mount point.
  *
  * @param[out] properties the resulting properties
- * @return true when the properties were successfully loaded and the result was set
+ * @return true when the properties were successfully loaded (they might still be empty strings!)
  */
 bool loadBootSettings(BootSettings& properties);