Last Date Track modified (RB not OS)

Add a column for the last date a track was modified in RB.  This way you can look for tracks that you just modified (Mem cue, cue points, Any metadata). Would be helpful for library management and tracking fo what you have done to files. 

Mistakenly add a cue point during your set, accidently make changes to metadata while playing.  You could easily find what needed to be fixed.