Remove unneeded import

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Updater (GUI): rely on Java6' convertRowIndexToModel() method

Earlier, we tried very hard to stay compatible with Java
1.5, but it gets too tedious to do so. So let's use the
JTable#convertRowIndexToModel(int) method instead of rolling our own
emulation thereof.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Updater: remove the LabeledFile hack

That hack allowed us to emulate our own TableModel, but it connected
the core too tightly to the Updater GUI's implementation.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Updater (GUI): switch on row sorting

Now that we use Swing in compliance with Java6' model, we can reap
the benefits.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'sortable-updater'

With this, the Swing GUI of the updater allows you to sort the data by
clicking on column headers.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>