Log Message:
Update stfl from 0.21 to 0.22 ("a pure bugfix release", with no new \ 
features)
and fix several packaging bugs:

- stfl is a library, so usually a runtime dependency.  The buildlink file
   originally registered as a build-time dependency, this is fixed now.
- Ensure stfl registers a proper runtime library search path in pkg-config.
- Create a symlink for just the major release number of the library.
   It registers a soname of libstfl.so.0, but this file is not installed.

Also reset the original package maintainer's email address to pkgsrc-users@.
I emailed him with this patch and he indicated no longer being interested in
maintaining this package, and neither am I (at the moment).