Change Details

`make check` `test_runner.py --extended` [x] IBD with -checkpoints=0 and -assumevalid=0 on mainnet: OK up to at least height 216000 (2013 January) [ ] IBD testnet up to ~2013 with assumevalid off

`make check` `test_runner.py --extended` [x] IBD with -checkpoints=0 and -assumevalid=0 on mainnet: OK up to at least height 216000 (2013 January) [x] IBD with -checkpoints=0 and -assumevalid=0 on testnet: OK up to at least height 230000 (2014 May)

`make check` `test_runner.py --extended` [x] IBD with -checkpoints=0 and -assumevalid=0 on mainnet: OK up to at least height 216000 (2013 January) [ x] IBD with -checkpoints=0 and -assumevalid=0 on testnet: OK up to ~2013 with assumevalid offat least height 230000 (2014 May)