Allow subtitle downloading (#11)

* Added subtitle options to media profile model

* Updated media profile form

* Adds subtitle-based options in options builder

* Updates metadata parser to include subtitles

* Adds subtitle_filepaths to media_item

* renamed video_filepath to media_filepath

* Added more fields to media profile show page

lib/pinchflat/media/media_item.ex

@@ -11,12 +11,16 @@ defmodule Pinchflat.Media.MediaItem do
   alias Pinchflat.Media.MediaMetadata
 
   @required_fields ~w(media_id channel_id)a
-  @allowed_fields ~w(title media_id video_filepath channel_id)a
+  @allowed_fields ~w(title media_id media_filepath channel_id subtitle_filepaths)a
 
   schema "media_items" do
     field :title, :string
     field :media_id, :string
-    field :video_filepath, :string
+    field :media_filepath, :string
+    # This is an array of [iso-2 language, filepath] pairs. Probably could
+    # be an associated record, but I don't see the benefit right now.
+    # Will very likely revisit because I can't leave well-enough alone.
+    field :subtitle_filepaths, {:array, {:array, :string}}, default: []
 
     belongs_to :channel, Channel