Add extension filter to associated files for Post Processing.

Allow the user to filter the associated files, that way it only moves
what the user wants (just subs for example).
This is useful for those that don't know how or have the ability to setup a cleanup script in their download client or have to maintain that list.

+ Move function to helpers
Change Womble section parameter.

Two feeds (sections) are needed now to cover the same results.
As a quick fix merge them into one new feed.

Used append, because extend only works in python 2.7
Merge branch 'Σ_port_change_womble_rrs_params' into Stable_Tornado
Fix for DB issues on new installs relating to database version checks.
Fixed DB issues related to displaying plot details for show episodes.