meson: Port install scripts for cmd.exe shells

meson: Port install scripts for cmd.exe shells

On Windows builds using Visual Studio-like compilers, we are using
cmd.exe shells, so we do the symlinking of the tools and man pages using
the commands that Windows provides.

Also, group the various programs and man pages together so that we have
single commands for each of the subdirs that we want to run the install
scripts, to make things simpler.