Remove waf entirely in favor of meson as the only supported build
system. Waf was officially deprecated in 0.36.0, and has not been
preferred over meson since 0.35.0.
version.h is essential for building, and its generation was done by a
shell script. Strictly speaking, python should in general be more
portable (windows), and would be better for the upcoming meson build to
simply just execute a python script. version.py has some small
differences with version.sh which shouldn't matter but they are noted
below.
- version.sh accepted several arguments that seemed useless (like
--cwd). These were removed from version.py.
- version.py takes either no arguments (prints the version) or it takes
exactly one argument specifying the complete path of where the header
should be generated.
- version.sh attempted to read a file named "snapshot_version". The
comments noted that this was for "daily tarball snapshots". Such a
file does not exist in the source tree, and it's not really clear that
anyone actually uses this. This logic was removed from version.py.
- version.py reads the SOURCE_DATE_EPOCH environment variable. Some
distros use this for reproducible builds. Technically you could also
just disable the build date but this is only a couple of extra lines
and maybe it's prettier than UNKNOWN.
- version.py also doesn't attempt to display timezone information in the
build date. It only shows UTC time.
