MSVC compilation has been broken since at least 1e417b72 ("All remaining
files in src/common belong to the event loop.") deleted
src/common/Makefile.nmake in 2018.

Except for src/ext, which we may not want to modify.

Closes ticket 32732.

Fixes bug 32371; bugfix on 0.4.0.1-alpha.

This updateVersions.pl script was one of the only essential perl
scripts left in out maint system, and was the only one that used
autoconf to fill in the script.

This script adds a feature to define an APPROX_RELEASE_DATE macro
that is updated when the version changes.  We'll use this to
implement prop297, so that we have an accurate view of when a
release date happens.