Add get_child_for_path
Improve get_child docs
Fix as_private behavior
Default to as_private=True
Actually strip the private key when requested
Just set private_key to None, don't delete it
Add tests for get_child_for_path
strip_private_key returns a copy
Fix pub/M errors
Can't pass as_private to every get_child, have to do it at the end.
Use setUpClass to drop tests from 12 to 8 seconds
More setUpClass to drop the tests down to 7 seconds
Add failing test for restoring from a public node.
Fix insidious bug for restoring from public keys
s/strip_private_key/public_copy/
Make sure to have consistent types on long/int params
get_child_for_path docs
Add unittest2 to requirements-dev for travis
Force py2.6 to use unittest2
python3 doesn't like unittest2