load settings from db, use api to change settings

+ add route to get all settings
+ add route to set any setting
+ add untested migration to add settings into settings db
+ compress json in api responses using FlaskCompress
+ serve gziped assets if browser accepts encoded files
+ misc

app/migrations/v1_3_0/__init__.py

@@ -277,3 +277,26 @@ class RemoveAllTracks(Migration):
         with SQLiteManager() as cur:
             cur.execute(sql)
             cur.close()
+
+
+class UpdateAppSettingsTable(Migration):
+    @staticmethod
+    def migrate():
+        drop_table_sql = "DROP TABLE settings"
+        create_table_sql = """
+        CREATE TABLE IF NOT EXISTS settings (
+            id integer PRIMARY KEY,
+            root_dirs text NOT NULL,
+            exclude_dirs text,
+            artist_separators text NOT NULL default '/,;,&',
+            extract_feat integer NOT NULL DEFAULT 1,
+            remove_prod integer NOT NULL DEFAULT 1,
+            clean_album_title integer NOT NULL DEFAULT 1,
+            remove_remaster integer NOT NULL DEFAULT 1,
+            merge_albums integer NOT NULL DEFAULT 0
+        );
+        """
+
+        with SQLiteManager(userdata_db=True) as cur:
+            cur.execute(drop_table_sql)
+            cur.execute(create_table_sql)