Lua telemetry screens. Still not finished:
- the scripts need to be wakedup even when not displayed
- I only tested telem0.lua, but theorically we could have 7 telemetry
screens
Now telem0.lua replaces the voltages screen and telem1.lua .. telem7.lua
are allowed. The user could now have 1+7+3+1=12 telemetry screens!
background function added to Lua scripts (used only in telemetry
scripts)
Events are transmitted to the Lua telemetry screens. Menus are displayed
over those screens (needed at least for Reset Telemetry/Flight)