Table: Added comment about rebuild() method deprecation
Table: Simplify reflow refresh
Table: Calculate which cells to unlock inside _unlockCells()
Table: Split locked-column-recording/restoring into a pair of functions
Table: Restore both forced-hidden and forced-shown columns at refresh()
Table: Simplify and speed up tests
Table: Make sure column is hidden for testing .prop( "checked", false )

Sometimes the column starts out as not visible, and sometimes it starts out as
visible. Before making sure that .prop( "checked", false ) has no effect, the
column must be rendered invisible irrespective of its starting state.