Add collection sync features

[j2ghz]

• Add option not to sync Collections https://emby.media/community/index.php?/topic/57494-emby-not-communicating-with-trakt-anymore/page-3#entry703884
• Remove missing items from Collections https://emby.media/community/index.php?/topic/65593-trakttv-syncing-library-to-trakttv-does-note-remove-items-removed-the-library/
• Change the hardcoded API keys to working ones for easier development
• Try improving descriptions in settings page:

- On the next request to the Trakt API, this PIN will be exchanged for tokens, and the text field will be cleared. You can input a new PIN to get new tokens.
+ When the pin is successfully exchanged for a token, it is deleted from this field. Afterwards, the hidden token is used.

- If checked, Emby will only sync from Trakt during the Trakt scheduled tasks.
+ If checked, Emby will sync with Trakt during the Trakt scheduled tasks. If unchecked, watch states on Trakt will not be changed. The scrobble feature will still work even if unchecked (sending realtime progress updates and marking the items as watched immediately when finished).

- When enabled, all data sent to trakt is logged.
+ When enabled, all data sent to trakt is logged. Use this when posting logs to report a problem, together with debug logging.