Reverting r465. Based on Stephen's example: stp-tests/crypto-tests/factoring-12bitsx1...

Reverting r465. Based on Stephen's example: stp-tests/crypto-tests/factoring-12bitsx12.stp this makes division about 50% faster.

Confirming what Stephen identified, varying just the bvdiv encoding:

crypto2: 42sec vs 32sec
simplifying minisat: 65s vs 37s
core minisat: 65s vs 43s

However, r600 solved this problem the fastest I've seen: 14 seconds. But that was cryptominisat. Cryptominisat2 is now in the trunk. So I suspect that this reverts a change that made division faster on cryptominisat, but slowed it down on the others (including cryptominisat2).

git-svn-id: https://stp-fast-prover.svn.sourceforge.net/svnroot/stp-fast-prover/trunk/stp@704 e59a4935-1847-0410-ae03-e826735625c1