Fix annoying problem with DNS failures.
Try to use latest pycoin.
Change default depth from 2 to 1.
Revert "Try to use latest pycoin."

This reverts commit 3dca51c2257d23f2dccd37411e1d5bf6fe26bcb1.

Something weird is going on and it's too late to debug.
Try to use latest pycoin.
More refactoring.
More refactoring.
First crack at test_get_mined_block.
Improve tests.
The test_get_mined_block test seems to be working.
Generalize network.
Checkpoint.
Get some tests working.
Get test_BlockChain tests working.
Use headers in BlockChainStore.
Include actual block/headers in block chain callback.
More tests fixed.
Fix locking.
First crack at wallet.py.
Get the wallet quitting after we catch up.