Added a new sync that uses hash

Added a new sync that uses hash and sqlc for the queries. Added db
migration. Started adding a config file.

db/queries/song.sql

@@ -0,0 +1,41 @@
+-- name: ClearSongs :exec
+DELETE FROM song;
+
+-- name: ClearSongsByGameId :exec
+DELETE FROM song WHERE game_id = $1;
+
+-- name: AddSong :exec
+INSERT INTO song(game_id, song_name, path, file_name, hash) VALUES ($1, $2, $3, $4, $5);
+
+-- name: CheckSong :one
+SELECT COUNT(*) FROM song WHERE path = $1;
+
+-- name: CheckSongWithHash :one
+SELECT COUNT(*) FROM song WHERE hash = $1;
+
+-- name: GetSongWithHash :one
+SELECT * FROM song WHERE hash = $1;
+
+-- name: UpdateSong :exec
+UPDATE song SET song_name=$1, file_name=$2, path=$3 where hash=$4;
+
+-- name: AddHashToSong :exec
+UPDATE song SET hash=$1 where path=$2;
+
+-- name: FindSongsFromGame :many
+SELECT *
+FROM song
+WHERE game_id = $1;
+
+-- name: AddSongPlayed :exec
+UPDATE song SET times_played = times_played + 1
+WHERE game_id = $1 AND song_name = $2;
+
+-- name: FetchAllSongs :many
+SELECT * FROM song;
+
+-- name: RemoveBrokenSong :exec
+DELETE FROM song WHERE path = $1;
+
+-- name: RemoveBrokenSongs :exec
+DELETE FROM song where path = any (sqlc.slice('paths'));