Configuration secrets

As discussed in http://flexget.com/ticket/2523
Plugin mode
manager.py fixed
Added keep_extension option, default true

Sometimes it's desirable to be able to change a files extension with move plugin
Merge pull request #307 from Pretagonist/patch-1

Added keep_extension option, default true
Prevent imdb_list from crashing on movies with no year
Switch imdb_list to html5lib parsing and hack it to work
Make sure loglevels don't get touched when not needed. refs #2660
Remove `Job` class, merge the important bits of it straight to `Task`
Move Tee class to utils
Refactor task queue and execution to be in manager
Strip down scheduler to just queue executions
make imdb_list not assume the number of movies on a page is 250

issue discussed here:
- http://flexget.com/ticket/2663#comment:8
Merge pull request #310 from dj-nitehawk/develop

Make imdb_list not assume the number of movies on a page is 250
Fix some references to removed scheduler.execute
Move task execution to own thread to handle signals/ctrl-c gracefully
Move BufferQueue to tools
Merge pull request #249 from tarzasai/config_secrets

Configuration secrets
Actually fix imdb_list with movies with no date.
Fix ipc checking for tasks already in the queue.
Move scheduler starting back to webui code.