Fix typo for Base::Demangle.
Rename associative to commutative as it should have been.
Merge pull request #120 from mpark/typo

Fix typo for Base::Demangle.
Merge pull request #121 from mpark/renaming

Rename associative to commutative as it should have been.
jhm/status_line: If it's not a Real TTY, there's nothing to cleanup.

Non-real TTYs have a newline after every status message already.