unify library linking step 1

As discussed last week with leont in #toolchain - it's currently very difficult to create multiple loadable modules in on directory (using one Makefile.PL).

This is a request for comment whether the direction of movement is right before investing to much effort.

Missing: VMS

Next steps: create OS/2 VM, Win32 VM (or recruit Mithaldu) and install OpenVMS as described in http://www.heise.de/ix/artikel/Dolly-Digital-1355065.html (using FreeAXP?)...

Then do the same for dynamic_lib