Four years after the collapse of Lehman Brothers Holdings Inc. and the near-total paralysis of capitalism’s central nervous system — the moment fear completely overwhelmed greed on Wall Street — we are starting to see a few glimmers of hope. The good news: Several big banks have finally started taking steps to reform Wall Street’s out-of-control compensation system, which rewards bankers and traders with big bonuses for taking insane risks with other people’s money. The bad news: These banks are in Europe, and most of their U.S. cousins still just don’t get it.