Chart Title Localization

[greenrhyno]

Adds localization logic into the chart title generation function so that charts can be more fully translated.

Changes include:

• edited Translation type to include new keys
• added default sentence fragments for default english locale
• updated README to account for changes to the Translation interface

[greenrhyno]

@frabarz -- Do you think we should include a Spanish translation by default in the code?

[frabarz]

Nah, that'd ship with the package in all bundles, even if Spanish is not intended for use. The English default is enough to have a basis for the user to work with.

[greenrhyno]

Made the changes requested by Dave. Looks good to go.