tracker-sparql: Added command line options to make using SPARQL easier
tracker-sparql: Added command line options to make using SPARQL easier

Added:
--list-classes
--list-class-prefixes
--list-properties

This allows people to quickly find out what classes we support, the
prefix they can use for them (to make life easier) and the properties
associated with a class. The class prefix can be used to get
properties too.

hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker