Hourglass cursor not appearing when loading categories

[delphidabbler]

In the develop branch, the hourglass that is meant to appear when loading a category of packets from the XML file is not appearing when an unloaded category is selected.

[delphidabbler]

See also issue #8 where it is proposed to revert to using the "loading" messages in the button bar per v0.1.0 as removed in v0.2.0. This would obviate the need for fixing this bug since the hourglass would no longer be needed.