If the cursor moves from one register cell to another, refresh the register headers.
If trading accounts are on and the transaction is expanded then the headers
depend on the type of split the cursor is in.
Bug 735769: Enable price and shares cells in a split if it is not in the trans currency.
The label for the cells are changed to "Exch. Rate" and "Oth. Curr." in this case.
Merge branch 'maint'