Explicitly encoding published files as UTF-8.
Allowing unicode in YAML.
Always decoding as UTF-8.
Added dollar signs to shell commands.

Also fixed bugs with blank column headers and weird boolean types.
Added a test for blank columns.
Added doctests for boolean conversion.
Merge pull request #93 from jacebrowning/tutorial

Add dollar signs to all shell commands in the tutorial.
Merged branch 'master' into branch 'sphinx'.