[tlbuild] TL'12 pretest

[Karl Berry]

TL builders,

TL'11 is frozen forever and it's time to start the TL'12 pretest.

If anyone has remaining planned/desired changes to their respective
programs for TL'12 that are uncommitted, please say so.

I hope everything is stable, in which cases, we should consider the
sources (not scripts) frozen except for necessary bug fixes.

(Except for Asymptote; John B is still working on that.
Hope he comes through soon.)

I'll plan to check in new i386-linux binaries tomorrow to give things a
day to settle.

karl