Boolean fields should display a value if listed in the pane

[bacalj]

Hi - Boolean values do not show a value that makes sense if selected for the pane. If the field is set to "true", it shows as "Untitled", otherwise it shows as blank.

I made a pull request with a basic fix: #66. This shows "true", "false", or stays blank if the field has no value. The above works for my use-cases, but another idea could be to have it use the field title?

Thanks for the awesome plugin!