Before this patch:
- Command was matched if 'Command' field of docker-py
representation of Docker container ends with 'command' passed
to Ansible docker module by user.
- That can give false positives and false negatives.
- For example:
a) If 'command' was set up with more than one spaces,
like 'command=sleep 123', it would be never matched again
with a container(s) launched by this task.
Because after launching, command would be normalized and
appear, in docker-py API call, just as 'sleep 123' - with one
space. This is false negative case.
b) If 'entrypoint + command = command', for example
'sleep + 123 = sleep 123', module would give false positive
match.
This patch fixes it, by making matching more explicit - against
'Config'->Cmd' field of 'docker inspect' output, provided by docker-py
API and with proper normalization of user input by splitting it to
tokens with 'shlex.split()'.