Casio fx-CG series port (#324)

* Initial test - working on Linux

* Try to make it work with liba

* Stop using liba and the filesystem

* IT WORKS

* Key input, full res, fix some of the crashes

* Fix the hang when doing calculations

* Add some more key mappings

* Fix the square root issue

* Icons

* Better key mappings, brightness control, better gamma correction, more effficient framebuffer

* Cleanup stage 1

* Cleanup stage 2

* Make the build system build a g3a

* Make it not exit when you press the menu button

* Add Casio port to README

* Use omega-master instead of omega-dev

* Fix mistake with cherry-picking in the README

* Fix internal storage crash

* Fix compile error on Numworks calculators

* Upsilon branding

* Sharper icon

* Make the CI work

* Add power off and improve menu

* Map Alpha + up/down to the brightness shortcut

* Add missing file

* Fix web CI build

* Revert "Fix web CI build"

This reverts commit f19657d9fc.

* Change "prizm" to "fxcg"

* Add FASTLOAD option for Add-in Push

* Add some charatcers to the catalog on Casio and improve key mappings

* Build with -Os -flto

* Disable LTO for now as it's causing crashes

* Put back the fonts I accidently changed

I'd like to add an option for this though as I prefer the ones from Epsilon

apps/shared/continuous_function.cpp

@@ -270,7 +270,7 @@ void ContinuousFunction::rangeForDisplay(float * xMin, float * xMax, float * yMi
   }
 
   if (!basedOnCostlyAlgorithms(context)) {
-    Zoom::ValueAtAbscissa evaluation = [](float x, Context * context, const void * auxiliary) {
+    Zoom::ValueAtAbscissa evaluation = [](float x, Context * context, const void * auxiliary) -> float {
       /* When evaluating sin(x)/x close to zero using the standard sine function,
        * one can detect small variations, while the cardinal sine is supposed to be
        * locally monotonous. To smooth our such variations, we round the result of