Set default value for label if no value is supplied.
Coding Standards

Changed to using null instead of '' and remove the ': ' at the end of the label value. (Though I myself quite like this..)
Spaces around equals sign.
Updated to use ucwords instead of ucfirst

This ensures each word is capitalized instead of just the first.
Merge pull request #1022 from wesleyh/master

Proposal: Default value for labels.