Release 0.5.1 "Talents": More RPL commands

This release focuses on rounding up various useful RPL commands
and bringing RPL a bit closer to feature-complete.

New features:
* Portable bit pattern generation commands, `gray` and `rgb` (#617)
* Add support for packed bitmaps (#555)
* Implement RPL `case` statement, extended with `case when` (#374)
* `Beep` command (#50)
* `List→` command (#573)
* `Size` command (#588)
* `Str→` command (#590)
* `Obj→` command (#596)
* Add flag to control if `0^0` returns `1` or undefined behaviour (#598)
* Unicode-based `Num` and `Chr` commands, `Text→Code` and `Code→Text` (#597)
* `IP` and `FP` commands (#601)
* Percentage operations `%`, `%CH` and `%T` (#602)
* `Min` and `Max` operations (#603)
* `Floor` and `Ceil` operations (#605)
* `Get` with a name argument (#609)
* `Put` command (#610)
* `Head` and `Tail` commands (#614)
* `Map`, `Reduce` and `Filter` commands (#613)

Bug fixes:
* Ensure rounded rectangles stay within their boundaries (#618)
* Prevent auto-power-off for long-running programs (#587)
* Fix old-style RPL shortcuts for `FS?C` and the like
* Add `FF` shortcut for `FlipFlag`
* Fix rendering of `<`, `>`, etc in old-style RPL compatibility mode (#595)
* Update various menus
* Evaluate program arguments in `IFT` and `IFTE` (#592)
* Evaluate algebraic expressions in `if`, `while` and `case` (#593)
* Load variables from state file in correct order (#591)
* Avoid truncation of state file when ASCII conversions occur (#589)
* Clear debugging state more completely after `kill` (#600)
* `Wait` no longer makes it harder to stop a program (#619)
* `mod` no longer gives wrong result for negative fractions and bignums (#606)
* No longer strip tags in non-numeric arithmetic operations (#607)

Improvements:
* Small updates to demo file
* A long `Wait` command allows the calculator to switch off (#620)
* Centering of variable names in `VariablesMenu` (#610)
* Makefile `check-ids` target to check if commands are in help or menus (#615)

Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>

src/dm32/qspi_crc.h

@@ -1,4 +1,4 @@
 
-#define QSPI_DATA_SIZE  1547060
+#define QSPI_DATA_SIZE  1550020
 #define QSPI_DATA_CRC  0x000cfed6
 

src/dm42/qspi_crc.h

@@ -1,4 +1,4 @@
 
-#define QSPI_DATA_SIZE  1543404
+#define QSPI_DATA_SIZE  1546156
 #define QSPI_DATA_CRC  0x000cfed6