build 2.2-stable worlds on 3.0-current systems again. objformat
calls getobjformat(), which doesn't exist in 2.2's libc.
Technically there should have been a version number bump when it was
added in -current. But it's used in so few places that it hardly
seems worth that. Besides, the objformat program is very heavily
used during a make world; it won't hurt to have it load a little
faster.
Move a.out libraries to /usr/lib/aout to make space for ELF libs.
Make rtld usr /usr/lib/aout as default library path.
Make ldconfig reject /usr/lib as an a.out library path.
Fix various Makefiles for LIBDIR!=/usr/lib breakage.
This will after a make world & reboot give a system that no
longer uses /usr/lib/*, infact one could remove all the old
libraries there, they are not used anymore.
We are getting close to an ELF make world, but I'll let this
all settle for a week or two...