Capture Interfaces dialog cleanup.

Capture Interfaces dialog cleanup.

Apply layouts as needed to allow resizing. Select the interface list by
row. We might want to switch the interface list to a QTreeWidget. Today
I learned that you can make QGroupBox titles checkable. Do that where we
enable and disable groups of items. Flatten all of the group boxes.
Change the output format combo to radio buttons. There are only two
choices and we have lots of real estate available. Use a
QDialogButtonBox so Qt can size and order the buttons appropriately.

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@54052 f5534014-38df-0310-8fa8-9805f1628bb7