Added LibGUI, and updates to EventDemo

[jfrickmann]

LibGUI shows a way to create a GUI with buttons, menus etc.

[rotorman]

Tested both apps on RM TX16S with b5e4f6e3 (from https://github.com/dlktdr/edgetx/tree/trainer_gui).

First LibGUI. If I click Exit button on the GUI, I get an error:
ERROR() in refresh(): /WIDGETS/LibGUI/loadable.lua:159 attempt to call field exitFullScreen (a nil value)

Second EventDemo. Sometimes by touching, the EVT_TOUCH_FIRST and EVT_TOUCH_BREAK stay flickering some seconds, even after I have let go the finger.

Am I using a wrong (old) firmware to test this, or is there an issue in the apps?

[jfrickmann]

Tested both apps on RM TX16S with b5e4f6e3 (from https://github.com/dlktdr/edgetx/tree/trainer_gui).

First LibGUI. If I click Exit button on the GUI, I get an error:
ERROR() in refresh(): /WIDGETS/LibGUI/loadable.lua:159 attempt to call field exitFullScreen (a nil value)

Second EventDemo. Sometimes by touching, the EVT_TOUCH_FIRST and EVT_TOUCH_BREAK stay flickering some seconds, even after I have let go the finger.

Am I using a wrong (old) firmware to test this, or is there an issue in the apps?

You need e5b5c412536870ff6c674437bd8db56edcc4f4ef for exitFullScreen() to be available.
The latest event is shown for 4 sec. - see line 187-190 in loadable.lua.