libtracker-miner: Add single tracker-miner.h header.
libtracker-miner: Add single tracker-miner.h header.

This should be the only include point from now on to libtracker-miner.
All code including individual libtracker-miner headers in Tracker has
been updated to #include <libtracker-miner/tracker-miner.h>.

GNOME/libmediaart,GNOME/libmediaart