Torrent fixes and log crash

- Fixes (likely) crashed with self.log usage left since axing plugin base class
- Refactored Torrent class for cleaner API
- Included modify_torrents plugin (refs #1775)
- Fixed Torrent unit tests, there are some bugs still


git-svn-id: http://svn.flexget.com/trunk@3251 3942dd89-8c5d-46d7-aeed-044bccf3e60c
Ability to turn configuration pre-check off with  comment.

git-svn-id: http://svn.flexget.com/trunk@3252 3942dd89-8c5d-46d7-aeed-044bccf3e60c