Retiring static libpam support

[Dag-Erling Smørgrav]

Currently, libpam is built both dynamically (with modules in separate
files which it dlopen()s, like everybody else does) and statically
(with the modules compiled-in).  This is a major headache, because the
static modules need to be built before the static library, but the
dynamic library needs to be built before the dynamic modules, so we
have quite a bit of magic (thanks ru!) to build libpam in two passes.
There's also quite a bit of highly non-portable magic in OpenPAM to
support static linkage.

The funny thing, though, is that nothing in our tree acutally uses the
static libpam (unless you have NO_SHARED= in make.conf).  Therefore,
I'd like to remove the ability to build a static libpam altogether,
unless someone can come up with a very good reason not to.

DES
-- 
Dag-Erling Smørgrav - des at des.no