[OS/2] Revert 47a9c9b17 due to fixed SIGFPE in JS.

See #25 for more info.
[OS/2] Make packager work again.
[OS/2] Add package-symbols make target.

This target generates a .zip file with .dbg or .xqs files for all
distributed .exe and .dll files. It is intended to be unzipped to the
same directory as the main package for getting crash reports with
full debug info.
[OS/2] Update README and CHANGES for release 24.3.0 OS/2 Beta.