Added default row, and configured current row to stay updated when metadata
updates.

In addition, blank spaces now represent the default data rate, and when
clicking "Apply" the default value is sent instead of 0.
Fixed indentation issues.
Renamed frozen table with copy-paste class.
Zeros are no longer acceptable input values.
Fixed bandwidth calculations. Now they use the default UAVO metadata
when the cell is empty.
Attempt at deleting cells. Works moderately well, but has a weird bug by
    which a cell must be clicke on after it has been deleted.
Prevent cursor selection of "Default" and "Current" columns.