Fix reading compressed files where there is a partial run of clusters that are uncompressed at the end of the file.  Reported by bsobel.
Fix reading compressed files where there is a partial run of clusters that are uncompressed at the end of the file.  Reported by bsobel.

breezechen/DiscUtils,breezechen/DiscUtils,quamotion/discutils,drebrez/DiscUtils