Try to explain better where and why Eliot is useful.
Address review comment: Try to explain that Eliot can work for simple application as well.
Merge pull request #138 from ClusterHQ/rebranding-137

Try to explain better where and why Eliot is useful.

Fixes #137.
Merge remote-tracking branch 'refs/remotes/origin/master' into unicode-files-135
Address review comment: ujson usage should now be covered by one of the tox test environments.
Address review comment: Mention Python 2.
Address review comment: Make _FileDestination less private, since it
crosses module boundaries.
Address review comment: Explain 5 second wait.
Address review comment: Clarify tests.