Measurement log manual parameter column doesn't update

[jmizrahi]

In the measurement log, if a manual parameter already exists as a column, and that manual parameter is then added to a scan, the column value doesn't update, even after removing and re-adding the column.

Also, if the value of a manual parameter is changed, the value displayed in the column changes with a delay (presumably dataChanged is not emitted).

[jmizrahi]

Also, as an addendum to this, manual parameters cannot be removed.