Log Message:
nss: fix interoperability with openssl

For a long time now (at least 15 years), the installed pkg-config
file also linked against libsoftokn3, which is wrong according to
upstream. This library is only intended to be loaded as a module.

Having this library linked added symbols to the namespace that conflict
with openssl symbols. This had caused problems before, and patches
had been added to rename symbols to avoid this conflict.

Instead, fix this correctly by not linking against libsoftokn3.

Switch to using the pkg-config and nss-config files provided in the
distfiles instead of pkgsrc-specific ones.

Remove now unneeded symbol-renaming patches.

Remove DragonFly patches while here.

Bump PKGREVISION.