Merge pull request #377 from acka47/context-adjustment

Correct spelling of tableOfContents.
Add remaining GND preferredName* properties to context (#318)
Merge pull request #379 from lobid/issue-318-context

Add remaining GND preferredName* properties to context
Add rdf:type bibo:Map for 902 "Karte", see #270
Merge pull request #372 from dr0i/issue-270

Issue 270: classify maps as rdf:type bibo:Map
Add longitudeAndLatitude to context.