Update tv.py

Removed weakref, caused issues with searching and downloads
Update network_timezones.py

Fix for timezone conversion issues.
Reverted episode cache changes
Reverted episode cache changes
Reverted episode cache changes
Fix, update and add some network specific logos as seen on the home page in "poster" view mode.
Fix for Newznab providers when searching for a show without a tvrage id we use the name of the show. If the show name is more than one word we are using a `_` as our delimiter which works fine unless the NN provider uses sphinx.. as the underscore then is used as part of the show name.. thus we always get back no results. We should just use `.` as it works for both sphinx and non sphinx servers. Tested this out on nzbs.org / nzb.su (sphinx) / sbi (non sphinx).
Merge pull request #597 from adam111316/usenet-crawler-fix

Fixes searching with usenet-crawler
Fixed language and subtitle issue for new shows.

Subtitle and language opts where ordered backwards causing incorrect
values to be set.
Test fix for home page none type error
Fixed urls

Fixed and replaced urls with proper ones for network timezones, tvdb
exceptions and tvrage exceptions.
Fixed for adding new shows
Replaced cherrypy with tornado which helped resolve our memory leak issue.
Fixed basic auth issues.
Improved startup/shutdown of tornado.
Fixed issues with notifications related to tornado.
Small fix for shutdown issues
Final fixes for proper shutdown of tornado
Improved startup and shutdown for tornado
Improved tornado async routines and shutdown routines.
Moved Tornado IOLoop to main() to resolve shutdown issues plus we now use IOLoop to control checks for startup tasks and background commands.