handle XDG_CONFIG_HOME specification ...

+ fix bug that caused duplicate artist color entries to db
+ check if app is windows (prep for windows build)
+ remove caribou migrations lib
+ rename all api blueprints to "api"
+ unregister child directories when customizing root dirs
+ misc

app/api/__init__.py

@@ -5,17 +5,8 @@ This module combines all API blueprints into a single Flask app instance.
 from flask import Flask
 from flask_cors import CORS
 
-from app.api import (
-    album,
-    artist,
-    favorites,
-    folder,
-    playlist,
-    search,
-    track,
-    settings,
-    imgserver,
-)
+from app.api import (album, artist, favorites, folder, imgserver, playlist,
+                     search, settings, track)
 
 
 def create_api():
@@ -27,14 +18,14 @@ def create_api():
 
     with app.app_context():
 
-        app.register_blueprint(album.albumbp)
-        app.register_blueprint(artist.artistbp)
-        app.register_blueprint(track.trackbp)
-        app.register_blueprint(search.searchbp)
-        app.register_blueprint(folder.folderbp)
-        app.register_blueprint(playlist.playlistbp)
-        app.register_blueprint(favorites.favbp)
-        app.register_blueprint(imgserver.imgbp)
-        app.register_blueprint(settings.settingsbp)
+        app.register_blueprint(album.api)
+        app.register_blueprint(artist.api)
+        app.register_blueprint(track.api)
+        app.register_blueprint(search.api)
+        app.register_blueprint(folder.api)
+        app.register_blueprint(playlist.api)
+        app.register_blueprint(favorites.api)
+        app.register_blueprint(imgserver.api)
+        app.register_blueprint(settings.api)
 
         return app