Adjusting field-markers

The delving:imageUrl should be an URL to an image, and here it is an URL
to a PDF document. Introduced the already existing
delving:fulLTextObjectUrl for the purpose of recognizing the PDF.
Making the LIDO record-definition delving-aware
Formatting
Merge pull request #32 from delving/lido-markers

Adjusting field-markers and making delving namespace aware. Formatting.