v0.3.1

Added

• Checkboxes update todo tiddler.
• Can now add project and context as separate columns to the display list.
• CSS classes to all rendered elements, allowing for custom styling.

Changed

• All columns (including built-ins) have column headers specified in
  configuration tiddler.
• Checkbox columns are now centered.
• General refactoring and cleanup.

v0.2.2

Initial release.