Adrian Ulrich d4062b18dd introduce song._flags
Adds a new _flags column to the song table which can be used to store bool flags for the song.

Currently, only 1<<0 is used to indicate that a song is outdated (but still valid)
2018-03-05 10:33:33 +01:00
..
2018-03-05 10:33:33 +01:00