Fixes and improves --series

- Adds display and warning notification that displays how many episodes
  current download is behind from last known episode. This helps spotting
  problems if episode advancement gets stuck.


git-svn-id: http://svn.flexget.com/trunk@3241 3942dd89-8c5d-46d7-aeed-044bccf3e60c
Removed leftover comment.



git-svn-id: http://svn.flexget.com/trunk@3242 3942dd89-8c5d-46d7-aeed-044bccf3e60c
Minor query tweak.

git-svn-id: http://svn.flexget.com/trunk@3243 3942dd89-8c5d-46d7-aeed-044bccf3e60c