lua51/lua52 packages and multiversion support

[David Holland <dholland-pkgtech%netbsd.org@localhost>]

I have lua51 and lua52 packages and what appears to be working
multiversion support.

This subsumes everything alnsn@ posted the other day (as far as I can
tell) except for his work to make the lua51 and lua52 packages
installable simultaneously. It also doesn't include agc's builtin.mk.
However, I think it should be reasonably straightforward to apply all
of those things on top of what I have.

The lua51 and lua52 packages I have are nearly identical to the
current package (and the version of it from before the update) except
for changing the package names and adjusting the version patterns.

Patches are here:
   http://www.netbsd.org/~dholland/tmp/lua/

I will commit this tomorrow or thereabouts unless there's a lot of
shouting, because it's readily susceptible to bitrot otherwise.

-- 
David A. Holland
dholland%netbsd.org@localhost