NEW:
- new UI language: Tamil
- Goodreads added as a search-site
- The 'genre' field replaced by a versatile tag system.
  Tag-substitution editor which can map tags from websites.
- Collecting many more website book-id's and making most available
  as book-links
- "Share" allows several "Citation" formats.

FIXES:
- GitHub #84 renaming default bookshelf
- GitHub #89, #92, #94 field visibility
- 979 ISBNs are now shown as 'valid'
- some author names like "Kim Stanley Robinson" were wrongly parsed
