Use reference counting in BATmsync. This should fix a problem that msync could get called on a heap that was deleted.
Use reference counting in BATmsync.
This should fix a problem that msync could get called on a heap that
was deleted.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb