Fix #222: Stop showing quotes in dialog text when deleting untitled draft

Fix #222. Check if draft to be deleted has a non-empty title before
showing quotes and the title name in the dialog text.
add new entry in preferences: send usage statistics
send stats opt out option prevent all analytics tracker to track any event
Tag titles are no longer written to the app log
Tag tables restructured to use tag/tag_type as primary key, lots of work left to do in order to support this new structure
Renamed topic variables/comments to tags
Moved ReaderTagType to its own class file
Added tag_type column to tbl_post_tags
Added tag_type wherever tag data is accessed
Code style cleanup, fixed bug that caused reader tag type to be saved as wrong type in prefs
Simplified DataRequestedListener
Adding/removing tags no longer uses just the tag name
Simplified adding/deleting a tag
Further simplified adding/deleting a tag
Adding a tag with the same name as a default tag now works
Moved db endpoint lookup to ReaderTagTable
reword _send usage_ checkbox summary
start or end session after reloading optout option
- SSL certs host name verifier: Switch to BrowserCompatHostnameVerifier host name verifier that works the same way as Curl and Firefox.
- When a certificate fails the host name verification with the default implementation, check it against our SSLTRust store. The certificate could be added to the trusted certificates pool.
Added code for tag preview backstack (issue #1492, PR #1496)