Bump version number, begin work towards 2021.4

FossilOrigin-Name: 6fe787a19ccc4b79e2754d2b974cbee3e8398d5976f89a4c3e48cfd9cd37c2d5

Makefile

@@ -1,5 +1,5 @@
-VERSION ?= 2021.1
-KEYPAIR ?= 2021-01
+VERSION ?= 2021.4
+KEYPAIR ?= 2021-04
 PREFIX ?= /usr/local
 DATADIR ?= $(PREFIX)/share/RETRO12
 DOCSDIR ?= $(PREFIX)/share/doc/RETRO12

RELEASE-NOTES

@@ -1,79 +1,11 @@
-# RetroForth 2021.1 Release Notes
+# RetroForth 2021.4 Release Notes
 
 ## Core Language
 
-* `choose` (and other conditionals) now treat non-zero as `TRUE` and
-  zero as `FALSE` instead of requiring a flag of -1 for `TRUE`
-* add \^ (ASCII ESC) to escape sequences in `s:format`
-
 ## I/O
 
-* improvements to some of the pipe related words in the `unix:`
-  namespace
-* reduced code size for each device handler slightly
-* added `abort` to Retro on Unix
-
-----
-
 ## Toolchain
 
-### Makefile
-
-* Small adjustments to reduce build time
-
-### C
-
-* retro-unu
-
-  - now supports user defined code and test block delimiters (C)
-
-* retro-muri
-
-  - supports changes from retro-unu
-  - now has separate passes for each step of the assembly process
-  - removed some unused variables
-
-### Python
-
-* retro-amalgamate.py added to generate a single file Python source
-* faster retro-extend.py
-* added retro-embedimage.py
-
-----
-
 ## VM
 
-### nga-c
-
-* reduced redundancy across the various implementations in C
-* removed an unused function
-* fixed several bugs in address stack handling in execute() that
-  were causing issues when including files in some circumstances
-
-### nga-python
-
-* now written using classes
-* no longer limited to 32 or 64 bit cells
-* uses Python functions to shadow some Retro words for better
-  performance
-* caches the Retro dictionary to improve lookup performance
-* embeds image as a Python source
-* now supports `-f`, `-i`, and `-u` command line parameters
-* improved error handling for invalid addresses
-* fixed a bugs in address stack handling in execute() that was
-  causing issues when including files in some circumstances
-
-### nga-nim
-
-* added initial Nim implementation by Jorge Acereda
-
-----
-
 ## Examples
-
-* added "2020 Advent of Code", days 1-5
-* added palindromic numbers detection (SVFIG challenge)
-* added bindings over curl
-* added muri with direct use of hex values
-* refactoring & general cleanups in Atua-WWW
-* Atua-WWW now ignores ?... appended to URLs

image/retro.muri

@@ -1,4 +1,4 @@
-# RETRO Core 2021.1
+# RETRO Core 2021.4
 
 RETRO Core is  a minimal Forth implementation for the Nga
 virtual machine. Like Nga this is intended to be used within
@@ -143,7 +143,7 @@ r 9999
 d 1536
 
 : Version
-d 202101
+d 202104
 ~~~
 
 Both of these are pointers. `Dictionary` points to the most

vm/nga-c/retro-image.c

@@ -3,7 +3,7 @@
 #define CELL int32_t
 #endif
 CELL ngaImageCells = 14991;
-CELL ngaImage[] = { 1793,14411,14948,14990,202101,0,10,1,10,2,10,3,10,4,10,5,10,6,10,
+CELL ngaImage[] = { 1793,14411,14948,14990,202104,0,10,1,10,2,10,3,10,4,10,5,10,6,10,
                        7,10,8,10,9,10,10,11,10,12,10,13,10,14,10,15,10,16,10,17,
                        10,18,10,19,10,20,10,21,10,22,10,23,10,24,10,25,10,68223234,1,2575,
                        85000450,1,656912,141,140,268505089,63,62,285281281,0,63,2063,10,101384453,0,9,10,2049,56,25,