Refactor modules into contexts (#78)

* [WIP] break out a few contexts, start refactoring fast index modules

* [WIP] more contexts, this time around slow indexing and downloads

* [WIP] got all tests passing

* [WIP] Added moduledocs

* Built a genserver to rename old jobs on boot

* Added a module naming check; moved things around

* Fixed specs

lib/pinchflat/media/media_item.ex

@@ -8,8 +8,8 @@ defmodule Pinchflat.Media.MediaItem do
 
   alias Pinchflat.Tasks.Task
   alias Pinchflat.Sources.Source
-  alias Pinchflat.Media.MediaMetadata
-  alias Pinchflat.Media.MediaItemSearchIndex
+  alias Pinchflat.Metadata.MediaMetadata
+  alias Pinchflat.Media.MediaItemsSearchIndex
 
   @allowed_fields [
     # these fields are captured on indexing (and again on download)
@@ -64,7 +64,7 @@ defmodule Pinchflat.Media.MediaItem do
     belongs_to :source, Source
 
     has_one :metadata, MediaMetadata, on_replace: :update
-    has_one :media_items_search_index, MediaItemSearchIndex, foreign_key: :id
+    has_one :media_items_search_index, MediaItemsSearchIndex, foreign_key: :id
 
     has_many :tasks, Task