* Use "#!/usr/bin/env perl" instead of "#!/usr/bin/perl", as this is better
practice (it allows e.g. /usr/local/bin/perl to work when executing via
the shebang)
* Use "use strict" and "use warnings"
* Declare variables with "my" as required by "use strict"
* Take an optional "srcdir" argument so that the scripts can find the icon
files in a location other than ./icons/ -- this will make building
outside of the source tree possible in the future
* Add a "this is a generated file" banner to the output, so that it can be
clearly recognized as a machine-generated file that should not be
hand-edited
* Minor regex tweaks
buttons. This requires some tools to convert .png images to that,
and that I put the characters in a two-dimensional grid in the
texture (since one-dimensional strip gets wider than the hardware
supports).
[git-p4: depot-paths = "//depot/solvespace/": change = 2138]