Fixed issue 200: if a heap contained multiple equal chunks, removing one of them resulted in removing all of them. Also replaced `List` by `IndexedSeq` for performance reasons.
Fixed issue 200: if a heap contained multiple equal chunks, removing one of them resulted in removing all of them.
Also replaced `List` by `IndexedSeq` for performance reasons.

sccblom/vercors,sccblom/vercors,sccblom/vercors,sccblom/vercors,sccblom/vercors