tracker-extract-epub: Extract more metadata, including author to nco:PersonContact

Added metadata: language, description, author family/given/other name,
description, subject, isbn and uuid.
tracker-extract-epub: Fix coding style for recent work from Martin
tracker-extract-epub: Make sure we consistently use g_{free|strdup|etc} APIs

There was some mixing of free/strdup with g_strdup().
tracker-extract-epub: Improve debugging
tracker-extract-epub: Fixed roles extracted
tracker-extract-epub: Fixed remaining strndup() cases and some coding styles
tracker-extract-epub: Fix ontology and sparql used so it's not rejected by miner-fs

https://bugzilla.gnome.org/show_bug.cgi?id=706530
Merge branch 'epub-metadata-improvements'