DefaultHwSettings: fix layout after module merge
UAVObjectManager: fix crash when sending data from category

Categories when selected allowed you to click send or save which
resulted in a crash.  This disables the buttons when they are when
categories are selected.  This required creating a new
CategoryTreeItem class to detect this.
Merge pull request #682 from peabody124/uavobjectmanager_category_crash

UAVObjectManager: fix crash when sending data from category
Merge pull request #680 from peabody124/hwsettings_layout

Modules tab broke layout for hw settings