1. All shell now allow to iterate over the output asynchronously, even if the shell command is not finished:
python
for line in shell("echo Hello; sleep 1; echo World", wait=False):
print line
2. API changes:
python
result = shell("echo Hello World")
assert result.stdout() = ["Hello World"] instead of result.out
assert result.stderr() = [ ] instead of result.err
assert result.exit_code() = 0 instead of result.xc