Examples used "code-block: pycon" instead of "python".
Cleaned up some code in messages.py.
reset() and panic() no longer reuse messages.
Fixed bullet points in changelog.
Messages are now copied on send.
Merge branch '1.1.x' into develop
Changed reset() and panic() back to reusing messages.
(This will work now that send() makes a copy.)
Rewrote send.py example.
Removed _setattr(). (No longer needed no that messages will stay mutable.)
Rewrote Message.copy() to make it more efficient.
This also made it simpler, which is good.
Documented copy on send.
Bumped version to 1.1.3.