This script takes ~1 second for startup, so calling it repeatedly for
each flag slows the Makefile considerably, and unnecessarily since it
can be called for all the flags at once.
Now make clean takes about 1.2s, instead of 3m45s.
The bitmap emoji tools are extended to create GSUB rules for character
sequences. The images are renamed to code the character sequence in their
filenames. New images are created for ASCII digits and number sign. A new
script is added to add cmaps to the files for backward compatibility.
Khaled Hosny