Make sure ping & pong tests are not garbage-collected.
Be more careful about not garbage collecting tasks.
Use weakset in InvCollector.
More strong references to Task objects.
Update comment.
Remove asyncio dependency from BlockChain.py.
Remove util.Queue.
Keep strong references to Task objects.
Add comments.
Merge branch 'local_master' into block_chain_27_friendly
Use callback version of BlockChain.
More strong references to Tasks.
Get blockwatcher working, sort of.
Merge branch 'deploy' into local_master

Conflicts:
	pycoinnet/examples/blockwatcher.py
Remove reference to Queue.
This release includes a pre-alpha release of blockwatcher, which dumps
new blocks that enter the block chain into a directory of your choice.
Merge branch 'master' into local_master
Include the requirements.txt contents in install_requires.
Make BlockChain work with Python 2.7.
Rename "config" to "state".